US and international forces in northeastern Syria were attacked with drones and rockets at least four times in the past 24 hours, though there were no casualties and only minor damage, a US military official said on Monday.
US forces came under attack three times on Sunday evening, including near the Al Omar Oil field and at a US base at al-Shaddadi, the official told Reuters.
Multiple drones were fired at US forces at the Rumalyn Landing Zone on Monday morning, the official said. One drone was shot down but another damaged four tents, the official added.
The attacks came after the US carried out two air strikes on Sunday against facilities it said were used by Iran-aligned groups, its third set of strikes in Syria in as many weeks.
US and coalition troops have been attacked at least 40 times in Iraq and Syria since early October. Statements, purportedly from militant groups, have said the assaults are in response to US support for Israel in the war in Gaza.
At least 56 US personnel wounded, but all have returned to duty
So far, at least 56 US personnel have suffered everything from minor wounds to traumatic brain injuries, though all have returned to duty, the Pentagon has said.
The US blames the attacks on groups backed by Iran - an assertion dismissed by Tehran which says the groups are acting on their own accord.
The United States has 900 troops in Syria and 2,500 more in neighboring Iraq, whom it says are on a mission to advise and assist local forces trying to prevent a resurgence of Islamic State, which in 2014 seized large swathes of both countries but was later pushed back.
Security analysts say there is growing concern that the Israel-Hamas conflict could spread through the Middle East and turn US troops at isolated bases into targets.