Iranian authorities had issued threats to retaliate against the United States after US bombers dropped bunker-busters on Iranian underground nuclear sites at the weekend, joining Israel's air war against Iran.
Qatar's defence minister, quoted by al-Jazeera TV, said its air defences had intercepted missiles directed at the Al-Udeid air base, the largest US military installation in the Middle East, situated across the Gulf from Iran.
Qatari authorities said there were no casualties in the attack, which it condemned and said it reserved the right to respond.
US officials also said there had been no US casualties.
The attack came shortly after Qatar closed its airspace as a precaution and the US and UK urged its citizens in the country to "shelter in place".
Iran co-ordinated its strikes on US bases, prompting the air space closure, a source familiar with the matter told Reuters on Monday.
The New York Times, which first reported the co-ordination, said Iran took the action to minimise casualties.
Just before the explosions, Iranian President Masoud Pezeshkian wrote on the social platform X: "We neither initiated the war nor seeking it. But we will not leave invasion to the great Iran without answer".
In addition, the US Ain al-Asad air base in Iraq had activated its air defence system out of concern of a potential attack, military sources told Reuters.
Earlier on Monday, Israel bombed a jail for political prisoners in Tehran in a potent demonstration that it was expanding its targets beyond military and nuclear sites to aim squarely at the pillars of Iran's ruling system.
Despite Iran's threats to challenge oil shipments from the Gulf, oil prices largely held steady, suggesting traders doubted Iran would follow through on any action that would disrupt global supplies.
Iranian Foreign Minister Abbas Araqchi met Russian President Vladimir Putin in Moscow as Iran sought backing from one of its last major power friends for its next steps.
with AP and PA