BAGHDAD, Nov. 14 (Xinhua) -- An Iraqi Shiite militia claimed on Tuesday responsibility for a drone attack on a U.S. military base in eastern Syria.

An armed group named "Islamic Resistance in Iraq" claimed in an online statement that its fighters had launched a booby-trapped drone toward the al-Omar oil field in the eastern countryside of Syria's Deir al-Zour province. It said the drone had hit its target.

Meanwhile, the Syrian Observatory for Human Rights, a Britain-based war monitor, confirmed that a U.S. base in the al-Omar oil field was attacked after midnight on Tuesday, without providing further details.

While casualties have not yet been reported, the attack by the armed group is believed to be part of a series of retaliatory measures against the U.S. forces amid the ongoing conflict in Gaza, said the observatory.

The incident marks the 35th recorded attack on U.S. bases in Syria since Oct. 19, it added.