US troops in western Iraq shot down two drones on Tuesday morning, Iraqi and US-led international coalition officials said.
No casualties were reported among the US or Iraqi troops stationed at Ain Al Asad Airbase in Anbar governorate.
"Two fixed-wing drones rigged with explosives were engaged and destroyed by defensive capabilities at the Iraqi Al Asad Airbase early this morning," the coalition official said. "The attempted attack was unsuccessful, all forces are accounted for."
The attack happened a day after the downing of two "kamikaze drones" flying near a US base at Baghdad's international airport.
Monday's attack was carried out a few hours after a ceremony to commemorate the second anniversary of the deaths of Iranian general Qassem Suleimani and Iraqi militia leader Abu Mahdi Al Muhandis in an American drone strike near the airport.
Photos shared by coalition of debris from Monday’s drones showed the messages “Leader’s revenge” and “Suleimani’s revenge” on the drones' wings.
In both attacks, the US troops brought down the drones with a counter-rocket, artillery and mortar defence system.
The US-led coalition was formed in September 2014 to fight ISIS, a few months after the terrorist group swept through large areas of northern and western Iraq.
It also operates in Syria, where ISIS is active in some parts.
After declaring ISIS defeated in late 2017, Iran-backed Iraqi politicians and militias have called for the withdrawal of US troops stationed in Iraq.
Tensions escalated in 2018, leading to tit-for-tat attacks and the January 2019 assassination of Suleimani and Al Muhandis.
Since then, militia attacks have become routine, forcing both Baghdad and Washington to reach an agreement for the US to end combat missions and to shift to a training and advisory role. There are however still 2,500 US troops stationed in Iraq.
"While we have ended our combat mission, we maintain the inherent right of self-defence," the coalition official said.
"These are attacks against Iraqi installations and an attack against the Iraqi people and the military that protects them. We maintain a minimal footprint on Iraqi bases – the coalition no longer has its own bases in Iraq."
Tuesday's attack was the third this year. The first one was on Saturday, when a roadside bomb went off next to a logistics convoy heading to a base hosting US troops.
On Wednesday night, five Katyusha rockets landed near Ain Al Asad Airbase in western Iraq where US troops are hosted, a government statement said. The attack caused no casualties, it added