BAGHDAD (AP) — Iran-backed militiamen withdrew from the U.S. Embassy compound in Baghdad on Wednesday after two days of clashes with American security forces, but U.S.-Iran tensions remain high and could spill over into further violence.

The withdrawal followed calls from the government and senior militia leaders. It ended a two-day crisis marked by the breach of the largest and one of the most heavily fortified U.S. diplomatic missions in the world.

The attack and its volatile aftermath prompted the Pentagon to send hundreds of additional troops to the Middle East an d U.S. Secretary of State...