The U.S. military intercepted multiple aerial drones targeting its troops stationed in Iraq early Wednesday, a U.S. official said, as U.S. officials are on heightened alert for potential attacks on American forces in the Middle East amid an escalating conflict.

U.S. forces shot down three drones in Iraq, where 2,500 American troops are stationed, said the U.S. official, who was granted anonymity to speak ahead of an announcement. Two were in the west, threatening troops at Al Asad air base, and one was in the north of the country, the official said.

No Americans were injured in the incident, the first such attack on U.S. positions in Iraq in least nine months, said the U.S. official. The official declined to say who was responsible for the attack.

The failed attack comes as Biden arrived in Israel on Wednesday to show support after Hamas militants launched a surprise attack on the country this month, a conflict that has escalated into an all-out war.

On Tuesday, a strike on a Gaza hospital killed more than 500 people. Both sides quickly traded blame for the attack, with Israeli officials saying the Islamic Jihad group was responsible.

Biden waded into the fray on Wednesday in Tel Aviv. He said the attack appeared to have been caused not by Israel but by “the other team,” citing information from his Defense Department.