The deaths of two U.S. service members in an Iranian attack in Jordan on Friday bring to 16 the total number American military personnel killed since the United States and Israel launched attacks on Iran on Feb. 28.

A U.S. official said the two most recent deaths were believed to have been caused by Iranian ballistic missiles launched in a barrage at a military base in Jordan. Several Iranian missiles were shot down, said the official, who spoke on the condition of anonymity because they were not authorized to speak publicly about the attack. But at least one penetrated U.S. and Jordanian air defenses.
President Trump has repeatedly said he would avenge the deaths of any U.S. soldiers, and the United States is almost certain to launch retaliatory attacks after a week of escalating strikes from both sides that appear to have ended an unsteady cease-fire reached in June.

The two U.S. service members killed were active-duty Army soldiers, the official said.

In recent days, Iran has been mixing up its tactics for attacking U.S. personnel on bases in the region, the official said, using a combination of medium-range ballistic missiles and one-way attack drones in the hopes of overwhelming air defense systems.

Six Army soldiers were killed during a March 1 attack on the port of Shuaiba in Kuwait. Another service member died of injuries he suffered during a March 1 attack on Prince Sultan Air Base, Saudi Arabia, and six Air Force personnel died when a KC-135 aerial refueling jet crashed in western Iraq on March 12.

The last known U.S. death from the war was a Navy helicopter pilot who was declared missing after an emergency landing in the Arabian Sea on July 1, which the Navy’s Fifth Fleet said was not believed to have been caused by enemy action. Days later, the Navy called off its search for the missing aviator.

The Pentagon’s casualty reporting protocols call for publicly identifying deceased service members only after 24 hours have passed since next of kin were notified. The names of troops wounded in action are not typically released.

More than 400 U.S. service members have been injured in the Iran conflict, according to the military’s Central Command, which directs military operations in the Middle East.

The command’s statement on Saturday said four American service members wounded in Friday’s attack were taken to Jordanian hospitals, and have been discharged.

More American troops received minor injuries and have been returned to duty, the statement said, but did not specify how many.

Eric Schmitt contributed reporting from Minnesota.