US and coalition forces at Al Asad Airbase in Iraq have intercepted two drones, a US defence official said on Tuesday, in the first such attack in months.
“All personnel are accounted for, and no injuries are reported,” the official said, noting that the situation was “evolving”.
The official did not say if the drones were armed, but Reuters cited sources as saying they were.
The attack is believed to be the first against US forces in Iraq since early February, and comes at a politically sensitive time as Washington prepares for high-level discussions over its presence in Iraq.
“In many ways, this attack comes completely out of nowhere, but in others, it makes perfect sense and fits within Iran's typical modus operandi,” Charles Lister, director of the Syria and countering terrorism and extremism programme at Washington's Middle East Institute, told The National.
“It's a pressure tactic designed to shape conditions ahead of next week's US-Iraq talks in Washington over the coalition presence on Iraqi soil.
“In times of calm, the US's position in those talks is strengthened, but in times of tension, the Iraqi government will be reminded of its need to answer to the ever-strong PMF constituency in Baghdad.”
Iraqi groups and others had been involved in a wave of attacks on American interests in the region after the start of the Israel-Gaza war.
The US responded by carrying out a series of strikes, mostly on Syria but also on Iraq, which in November prompted Baghdad to accuse Washington of a “breach of Iraqi sovereignty”.
The Iraq-based attacks stopped after the US and the Iraqi government began to engage in talks over a timeline for withdrawing American forces from the country.
But a powerful militia leader in Iraq warned late last month that all US interests in the region, particularly in Iraq, will be attacked if Washington supports any Israeli military operation against Lebanon.
Tuesday's strike also came just hours after Iranian Gen Ismail Qaani visited Tehran-linked proxy groups in Iraq and Syria.
“The intention, I assume, will be to coax the US into responding, which is unlikely to happen after this one attack, but if there are more to come, it will set up conditions for next week's talks perfectly as far as Iran is concerned,” Mr Lister said.