Two US F-15 fighter jets conducted an airstrike on a weapons storage facility in eastern Syria used by Iran’s Islamic Revolutionary Guard Corps (IRGC) and affiliated groups, the Pentagon announced Wednesday.

“This precision self-defense strike is a response to a series of attacks against U.S. personnel in Iraq and Syria by IRGC-Quds Force affiliates,” Defense Secretary Lloyd Austin said in a statement. “The President has no higher priority than the safety of U.S. personnel, and he directed today’s action to make clear that the United States will defend itself, its personnel, and its interests.”

“The United States is fully prepared to take further necessary measures to protect our people and our facilities,” he added. “We urge against any escalation.”
A senior military official said Wednesday evening that the facility, located in Maysalun, Syria, is believed to have housed weapons used in “many of the airstrikes that have taken place against our forces here in the region.”

“We’ve been watching it for a bit to ensure that when we struck the target, we would strike it at a time that we would be able to eliminate the use of the facility to the IRGC. … I watched the engagement, I can tell you that we’re pretty certain there were some secondary explosions that indicated that the facility was housing weapons that we believe are likely used in many of the strikes that have taken place against our forces here in the region,” the official said.

The official added that they are “very certain” Wednesday’s strike “did not involve civilian loss.”