A group calling itself the "Islamic Resistance in Iraq" launched drone strikes on the US Rumailan base in Syria’s Hasakah after 25 militants were killed in Israeli airstrikes against alleged pro-Iran militia sites.
The militia revealed in a statement that the attack was in response to "Israeli massacres against the people in Gaza" and as part of its "resistance against the US occupation in Iraq and the region."
Iranian-backed groups have launched over 100 attacks on US military bases in Iraq and Syria.
Explosions were heard at the American Kharab Al-Jir base in Rumailan countryside, eastern Syria, as a result of an attack with two successive batches of drones and missiles.
The American forces downed some of the drones; however, no causalities were reported as fighter jets of the international coalition to combat ISIS flew over the area, according to the Syrian Observatory for Human Rights (SOHR).
The Observatory documented 67 attacks against US bases in Syria since October 19.
At least 25 Iran-backed fighters were killed in air strikes on Friday night in eastern Syria, the Observatory added.
SOHR suggested that Israel may be behind the attack.
Headquartered in London, the war monitor said that the raids targeted posts of the Iranian militias in the Iranian security zone, posts in the 47th Regiment in the desert of al-Bukamal, a convoy belonging to the militias after entering the Syrian territory coming from Iraq, headquarters, a military shipment, an ammunition warehouse, and vehicles in al-Bukamal and its countryside near the Syrian-Iraqi border.
SOHR noted that Israel targeted Syrian territories 45 times since the war on Gaza in October, where it documented 28 attacks: 28 airstrikes and 17 rocket attacks by ground forces.
Those attacks destroyed 28 targets and left 77 combatants and two civilians dead.
Israel often targets sites in Syria to prevent Iran from strengthening its military presence in the region through its militias.
The US bases in SDF-controlled northeastern Syria have been targeted daily by rocket shells and drones since Israel declared war on Gaza.
There are nine US bases in Syria: one in al-Tanf, two in Deir Ezzor's countryside, and six in Hasakah.