Explosion rocked the skies of the Qatari capital Doha on Monday after Iran's threats to retaliate against the U.S. forstrikes on three Iranian nuclear facilities. The White House and the Department of Defense are aware of, and closely monitoring, potential threats to Al Udeid Air Base in Qatar, a senior White House official not authorized to speak publicly told USA TODAY. Iran has begun an operation against a US base in Qatar, Iran state TV has reported, according to CNN. The reports come as Israel stepped up airstrikes on Iran on Monday, hitting several locations the Israeli defense minister described as "regime targets" in Tehran, including the notorious Evin Prison and the internal security headquarters of Iran's paramilitary Revolutionary Guard. The Israel military said it struck several airports and access routes near Iran's Fordow enrichment site, which the U.S. bombed on Sunday. Across Israel, sirens sounded as people took to shelters amid reports of Iranian missile launches, including one that struck an electrical facility in southern Israel and caused power disruptions, Israeli media reported. The U.S. remained on alert with its40,000 troopsin the region two days afterPresident Donald Trumpordered the bombing of Fordow, a uranium enrichment facility deep inside a remote mountain in Iran, and facilities at Natanz and Isfahan. Many world leaders− including those from the UK, France and Germany − called for restraint and a return to the diplomatic table.And protesters in some U.S. citiessuch as the nation's capital and New York took to the streets to voice ardent opposition to intervention in Iran. The extent of the damageto the Iran nuclear sites remains a question mark since there has so far been no independent assessment. The International Atomic Energy Agency, which is the main agency that assesses Iran's nuclear program, was holdingan emergency meetingMonday. Developments: ∎ Trump is set to meet with his national security team at 1 p.m., according to his public schedule. The meeting comes after the president raised the prospect of an Iranian "regime change" in a statement on hissocial media platform Truth Social. ∎ Russian PresidentVladimir Putinhosted Iran's foreign minister in Moscow and told him there was no justification for the U.S. bombing of Iran, which he described as "unprovoked aggression,"according to the Kremlin. Putin added that Moscow is making efforts to assist the Iranian people. ∎ Iranian official Ebrahim Zolfaqari warned that the U.S. should expect severe consequences. "Mr. Trump, the gambler, you may start this war, but we will be the ones to end it," Zolfaqari said in English in a video shared Monday. Trump warned other countries Mondays not to supply nuclear weapons to Iran in response to U.S. bombing, after a former Russian president suggested the option. "The 'N word' should not be treated so casually,"Trump said in a social media post, referring to nuclear weapons.Trump was referring to asocial media post by Dmitry Medvedev, the former president of Russia, but questioned its accuracy. Medvedev's post suggested "a number of countries are ready to directly support Iran with their own nuclear warheads."−Bart Jansen TheIsraeli military released an urgent warningto residents in Tehran urging them to stay away from "security institutions" as they plan to continue pounding the capital city with airstrikes. "Dear citizens of Tehran, In the coming days, the Israeli army will continue its attacks against military targets in the Tehran region," read the statement posed Monday on X. "To maintain your personal safety, we ask you to stay away from weapons production centers, military bases, and security institutions affiliated with the regime." Tehran is one of the largest cities in the Middle East and is home to an estimated 9.5 million people. On Monday, Israel launched several strikes on the city, hitting near Evin Prison and several command and security operations centers. There are no U.S. forces at the military base in Syria that reportedly had come under mortar fire, a U.S. official said Monday. The official, who could not confirm whether an attack had occurred at the base, was not authorized to speak publicly about U.S. troop movements in the region. The alleged attack at a base in western Syria was first reported by Mehr, a news agency affiliated with the Iranian government. The Pentagon has been bracing for a counterattack after the U.S. airstrikes Saturday on three nuclear facilities in Iran. The Pentagon has sent an additional aircraft carrier strike group to the region and bolstered air defenses to protect troops in recent weeks following Israel's ongoing attacks on Iran. Militia groups, funded and supplied by Iran, have regularly fired rockets, mortars and drones at bases with U.S. troops in Iraq and Syria. Those attacks typically do not cause casualties or major damage. − Tom Vanden Brook Is it safe to travel abroad right now?Worldwide caution issued after US strikes on Iran Rep. Marjorie Taylor Greene has been one of Trump's most loyal supporters, but she's not holding back in slamming his decision to bomb Iran. In a second lengthy social media post since the bombing, Greene accused Trump of a "bait and switch" with his supporters. Greene wrote in the Monday post that she campaigned with Trump on a "MAGA agenda" that included "NO MORE FOREIGN WARS. NO MORE REGIME CHANGE. WORLD PEACE." Now, six months into Trump's second administration, Greene wrote "we are back into foreign wars, regime change, and world war 3." "It feels like a complete bait and switch to please the neocons, warmongers, military industrial complex contracts, and neocon tv personalities that MAGA hates and who were NEVER TRUMPERS!" Greene added. A Georgia Republican, Greene was among a vocal MAGA contingent warning against attacking Iran before Trump decided to go forward with the strike. Greene has remained outspoken, saying in an earlier social media post that "I can also supportPresident Trump… while disagreeing on bombing Iran and getting involved in a hot war that Israel started." −Sudiksha Kochi, Zac Anderson Trump on Monday urged "everyone" to "keep oil prices down" after U.S. airstrikes on three nuclear facilities in Iran. "EVERYONE, KEEP OIL PRICES DOWN. I'M WATCHING! YOU'RE PLAYING RIGHT INTO THE HANDS OF THE ENEMY. DON'T DO IT!" hewrote in a Truth Social post. It wasn't clear who he was referring to in the post. Ina follow-up Truth Social post,Trump urged the Department of Energy to "DRILL, BABY, DRILL!!! And I mean NOW!!!" −Sudiksha Kochi and Savannah Kuchar When asked about Trump's recent musings on regime change in Iran, White House press secretary Karoline Leavitt told reporters Monday that the administration and the U.S. military posture has not changed from its stated goal of taking out Iran's nuclear capabilities. "The president was just simply raising a question that I think many people around the world are asking," she said, adding that if Iran's government "refuse(s) to engage in diplomacy moving forward, why shouldn't the Iranian people rise up against this brutal terrorist regime?" She also told Fox News that Trump "believes the Iranian people can control their own destiny" — including by toppling their country's theocratic regime. U.S. stocks opened with little changeas the world waits to see whether Iran retaliates after asurprise U.S. strikeon Iran over the weekend. At 9:33 a.m. ET, the blue-chip Dow dipped 0.21%; the broad S&P 500 shed 0.13%; and the tech-heavy Nasdaq lost 0.52%. The benchmark 10-year Treasury yield slipped to 4.342%. Investors are worried how MIdeast turmoil could affect the economy, oil prices, inflation and interest rates. Oil prices initially rose to a five-month high but pared gains. They were last up 0.16% to $73.96 per barrel. − Medora Lee Leavitt said Iran was an "imminent threat" and that the U.S. strikes "took away Iran's ability to create a nuclear bomb." "They no longer have the capability to build this nuclear weapon and threaten the world," Leavitt said in an interview on ABC News. Her statement comes amid questions around the success of the strikes to destroy Iran's nuclear sites. While Trump and his administration remain adamant that the strikescaused "monumental damage," no independent assessment of the facilities has taken place. Misinformation and fears:Gen Z, Iran and the mass panic happening on TikTok The U.S. Embassy in Qatarissued an alerton its website warning American citizens to "shelter in place until further notice." It's unclear what exactly triggered the alert, though it comes amid high tensions in the region after the U.S. bombed several nuclear facilities in Iran. On Sunday, theState Department released an advisoryurging U.S. citizens worldwide to "exercise increased caution" as the conflict between Israel and Iran continued to escalate. Qatar's foreign ministry in a statement on Monday said recent advisories issued by embassies "do not necessarily reflect the existence of specific threats." The statement added the the security situation in Qatar is "stable." Iran's parliament voted Sunday in support ofclosing the Strait of Hormuz, a vital trade route that carries an estimated 20% of the world's oil and gas. The decision to close the strait ultimately belongs to Iran's Supreme National Security Council, which has yet to officially weigh in. Leavitt said the Iranian regime would be "foolish" to close the strait when asked whether the Trump administration would release more oil to dampen potential price hikes. "I can assure you the administration is actively and closely monitoring the situation in the Strait of Hormuz," Leavitt told ABC News. "The Iranian regime would be foolish to make that decision." −Savannah Kuchar and Bart Jansen Trump is set to meet with his national security team at 1 p.m., according to his public schedule, as tensions in the Middle East grow after the president ordered a trio of strikes at Iranian nuclear facilities on Saturday. In apost on his social media platform, Trump raised the prospect of regime change while officials in his administration said they were seeking to resume negotiations talks with Iran. "It's not politically correct to use the term, 'Regime Change,' but if the current Iranian Regime is unable to MAKE IRAN GREAT AGAIN, why wouldn't there be a Regime change??? MIGA!!!" Trump wrote. Following the latest round of Israeli missile strikes on Tehran, the Iranian judiciary's Mizan news agency said electricity was cut off in several city districts and that the situation at Evin Prison is "under control." The judiciary said on of the strikes in northern Tehran hit one of the main lines supplying the area, resulting in power outages. The notorious Evin Prison was built in 1971 and has housed political prisoners, Westerners and journalists used as bargaining chips by Iran. It has previously been targeted by sanctions, and human rights groups have long condemned the treatment of prisoners there. U.N. nuclear watchdog chief Rafael Grossi said he expects that U.S. bombing on Iran's Fordow nuclear enrichment site caused "very significant damage," but he added that the extent of any damage remains unclear as the International Atomic Energy Agency has not been able to carry out an inspection. "Given the explosive payload utilized and the extreme(ly) vibration-sensitive nature of centrifuges, very significant damage is expected to have occurred," Grossi said in a statement Monday to an emergency meeting of the International Atomic Energy Agency's 35-nation Board of Governors. Russian President Vladimir Putin on Monday told Iranian Foreign Minister Abbas Araqchi in Moscow that aggression against Iran was groundless. Putin made the comments at the start of Kremlin talks and said Russia, which has condemned the U.S. strikes, was ready to help the Iranian people. Iran and its hard-linesupreme leader, Ayatollah Ali Khameneiare almost certainly going to strike back in response tohistoric U.S. military strikeson three of its suspected nuclear facilities. But if history is any guide, that response could happen at any time − and anywhere, and in any form, former U.S. intelligence officials and diplomatic experts say. "Missiles, militias and acts of hostage-taking – that's their go-to" range of options, the Biden administration coordinator for the Middle East, Brett McGurk, said on CNN June 21. "I suspect Iran will have to do something."Read more here. −Josh Meyer The U.S. used more than a dozen multimillion-dollar,30,000-pound "bunker busters"tobomb Iranian nuclear facilitiesin the strike, known as Operation Midnight Hammer, marking the weapon's first operational use, according to the Pentagon. U.S. bomber planes dropped 14 of the massive bombs on three of Iran's nuclear facilities, Chairman of the Joint Chiefs of Staff Gen. Dan Caine said. The bombs used in the strikes, calledMassive Ordnance Penetrators, or MOPs, weigh 30,000 pounds each and cost millions to produce. MOPs, also known as the Guided Bomb Unit, or GBU-57, areGPS-guided weapons designedto burrow deep into underground targets, such as fortified tunnels or bunkers. The bombs are about 20 feet long and span 6 feet at their widest point.Read more here. − Cybele Mayes-Osterman Some lawmakers, including hard-line conservatives and key progressives, are calling the U.S. strikesa breach of the Constitution,. "The President's disastrous decision to bomb Iran without authorization is a grave violation of the Constitution and Congressional War Powers," Rep. Alexandria Ocasio-Cortez, D-New York,posted on X. Rep. Thomas Massie, R-Kentucky, responded to Trump's social media assessment of the attack withthe statement: "This is not Constitutional." TheWar Powers Resolutionof 1973 requires the president to notify Congress within 48 hours of military action. The law also limits the deployment of armed forces beyond 90 days in the absence of a formal declaration of war. − Savannah Kuchar Trump ordered the strikes on Iran's nuclear facilities, effectively joining a war that Israel started on June 13 when it began bombing Iranian nuclear and military infrastructure. Israel said it helped the U.S. coordinate and plan the strikes. Trump said all three sites were "totally obliterated." But an independent assessment has not yet been carried out. The International Atomic Energy Agency − the United Nation's nuclear watchdog − released a statement saying that so far it had not detected an increase in "off-site radiation levels," one of the feared consequences of the strikes. Vice PresidentJD Vanceinsisted Sunday that the U.S. is not entering an open-ended conflict in the Middle East. "We're not at war with Iran. We're at war with Iran's nuclear program." Vance said on NBC. Contributing: Reuters This article originally appeared on USA TODAY:Iran-US live updates: What is Iran's next move after US bombing?