The latest attack took place in the autonomous Kurdistan region in northern Iraq on Thursday, causing "no casualties" and "some minor damage to infrastructure," Pentagon spokesman Brigadier General Pat Ryder told journalists.

Since October 17, "US and coalition forces have been attacked at least 12 separate times in Iraq (and) four separate times in Syria," Ryder said, referring to the international coalition against the Islamic State jihadist group.

The attacks were carried out with "a mix of one-way attack drones and rockets," he said.

"We know that these are Iranian-backed militia groups that are supported by Iran and of course we hold Iran responsible for these groups," Ryder said of who is behind the attacks.

American forces in the Middle East are facing a spike in attacks linked to the latest war between Israel and Hamas, which began when the militant group carried out a shock cross-border attack from Gaza on October 7 that Israeli officials say killed more than 1,400 people.

Israel's retaliatory bombardment has killed more than 7,000 people, according to the Gaza health ministry -- deaths that have sparked widespread anger across the Middle East.

There are roughly 2,500 American troops in Iraq and some 900 in Syria as part of efforts to prevent a resurgence of IS, which once held significant territory in both countries but was pushed back by local ground forces backed by international air strikes in a bloody multi-year conflict.