A rocket attack on a base in Iraq wounded multiple US personnel on Monday, officials said, adding to already heightened regional tensions over an expected Iranian counterattack on Israel.

The rocket fire is the latest in a series of attacks targeting Ain al-Assad base in western Iraq, which hosts American troops as well as personnel from the US-led coalition against the Islamic State jihadist group.

"There was a suspected rocket attack today against US and coalition forces" at the base, a US defense spokesperson said. "Initial indications are that several US personnel were injured."

"Base personnel are conducting a post-attack damage assessment" and updates will be provided as more information becomes available, the spokesperson added.

US President Joe Biden and Vice President Kamala Harris were briefed on the attack, the White House said.

"They discussed the steps we are taking to defend our forces and respond to any attack against our personnel in a manner and place of our choosing," it said in a statement.

An Iraqi military source had earlier said that multiple rockets were fired at the base, with some landing inside it and another hitting a nearby village but not causing damage.

A commander in a pro-Iran armed group told AFP that at least two rockets targeted the base, without saying who had carried out the attack.

Another source in the group and a security source confirmed an attack occurred.

Such attacks were frequent early in the war between Israel and Hamas Palestinian militants in Gaza but since then have largely halted.

The latest rocket fire comes as fears grow of an attack by Iran and its allies on Israel in retaliation for the killing of top Hamas and Hezbollah figures in strikes last week either blamed on or claimed by Israel.

Series of attacks

The killings, with both Iran and Hezbollah vowing retaliation, are among the most serious series of tit-for-tat attacks that have heightened fears of a regional conflagration stemming from the Gaza war.

The Iran-aligned "Axis of Resistance" against Israel, which also includes Iraqi groups and Yemen's Huthis, have already been drawn into the nearly 10-month war.

Monday's rocket attack occurred after US forces carried out a strike last week on combatants who were attempting to launch drones that were deemed a threat to American and allied troops, a US official said.

The strike, which Iraqi sources said left four killed, was the first by American forces in Iraq since February.

There have been two recent attacks targeting bases hosting US and allied forces in Iraq -- on July 16 and 25.

Prior to that, US troops in Iraq and Syria had not been targeted since April. But attacks against them were much more common in the first few months of the Israel-Hamas war in Gaza, when they were targeted more than 175 times.

The Islamic Resistance in Iraq, a loose alliance of pro-Iran groups, claimed the majority of the attacks, saying they were in solidarity with Palestinians in Gaza.

In January, a drone strike blamed on those groups killed three US soldiers at a base in Jordan. In retaliation, US forces launched dozens of strikes against Tehran-backed fighters in Iraq and Syria.

Baghdad has sought to defuse tensions, engaging in talks with Washington on the future of the US-led coalition's mission in Iraq, with Iran-backed groups demanding a withdrawal.

The US military has around 2,500 troops in Iraq and 900 in Syria.