Three American service members were killed and “many” were wounded in a drone strike in Jordan, President Joe Biden said in a statement Sunday. He attributed the attack to Iran-backed militia groups.

They were the first U.S. fatalities in months of strikes against American forces across the Middle East by Iranian-backed militias amid the Israel-Hamas war in Gaza, increasing the risk of escalation.

Biden said the United States “will hold all those responsible to account at a time and in a manner our choosing.”

The attack took place in northeast Jordan, near the border with Syria.

There was no immediate reaction from Jordan, a kingdom bordering Iraq, Israel, the Palestinian territory of the West Bank, Saudi Arabia and Syria.

U.S. troops long have used Jordan as a basing point. Some 3,000 American troops typically are stationed in Jordan.

Since Israel’s war on Hamas in the Gaza Strip began, U.S. troops in Iraq and Syria have faced drone and missile attacks on their bases. The attack on Jordan marks the first targeting American troops in Jordan during the war.

Biden, who was in Columbia, South Carolina, was briefed Sunday morning by Defense Secretary Lloyd Austin, national security adviser Jake Sullivan and principal deputy national security adviser Jon Finer.

(AP)