AMERICANS INJURED IN ATTACK ON U. S. BASE IN IRAQ. (PHOTO).

Several U.S. personnel were injured in an attack against a military base in Iraq on Monday, three U.S. officials told Reuters, as concerns in the region mounted following last week's killing of senior members of militant groups Hamas and Hezbollah.

The officials, speaking on the condition of anonymity, said the suspected rocket attack took place at Al Asad airbase in Iraq. They said they were citing initial information which could change.

"Base personnel are conducting a post-attack damage assessment," one of the officials added.

Two Katyusha rockets on Monday were fired at the base in western Iraq, security sources said. One security source said the rockets fell inside the base.

Last week the U.S. carried out a strike in Iraq against individuals U.S. officials said were militants getting ready to launch drones and posed a threat to U.S. and coalition forces.

The U.S. is bracing for Iran to make good on its vow to respond to the killing of Hamas leader Ismail Haniyeh two days ago in Tehran - one in a series of killings of senior figures in the Palestinian militant group as the war between Israel and Hamas in Gaza rages.

The Pentagon has said it will deploy additional fighter jets and Navy warships to the Middle East, as Washington seeks to bolster defenses following threats from Iran and its allies Hamas and Hezbollah.