This photo shows a view of the Ain Al Assad air base hosting US forces in Iraq. AFP

Rockets were fired on Monday towards an Iraqi base hosting US troops days after an American strike killed four pro-Iran Iraqi fighters, and amid fears of regional escalation, Iraqi sources said.

"Rockets were launched at Ain al-Assad base" in Anbar province, said the military source.

While some "fell inside the base", one rocket landed on a nearby village without causing any damage, the source added.

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.

All sources spoke on condition of anonymity because they are not authorised to speak to the media.

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

But 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 weeks either blamed on or claimed by Israel.

The killings, with both Iran and Hezbollah vowing retaliation, are among the most serious series of tit-for-tat attacks that had already 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.

Agence France-Presse