WASHINGTON — Several U.S. personnel were injured in a suspected rocket attack at a military base in Iraq, U.S. defense officials said Monday, in what has been a recent uptick in strikes on American forces by Iranian-backed militias. And they said the U.S. was looking into reports of a possible second attack at the base.

Attack Comes as Tensions Rise

The attack comes as tensions across the Middle East are spiking following the killings last week of a senior Hezbollah commander in Lebanon and Hamas’ top political leader in Iran, in suspected Israeli strikes. Both groups are backed by Iran.

The U.S. defense officials said troops at al-Asad air base were still assessing the injuries and damage, and it appeared that as many as seven military troops and civilians were injured. Earlier Monday, Iraqi security officials confirmed the attack, but no group has claimed responsibility.

The officials spoke on condition of anonymity to discuss military operations. The White House said the president and vice president were briefed on the attack.

Related Story: Why Is Iran Expected to Attack Israel? What to Know About the Crisis.

In recent weeks, Iranian-backed Iraqi militias have resumed launching attacks on bases housing U.S. forces in Iraq and Syria after a lull of several months, following a strike on a base in Jordan in late January that killed three American soldiers and prompted a series of retaliatory U.S. strikes.

Between October and January, an umbrella group calling itself the Islamic Resistance in Iraq had regularly claimed attacks that it said were in retaliation for Washington’s support of Israel in its war against Hamas in Gaza and were aimed at pushing U.S. troops out of the region.