On Wednesday, the U.S., military said two F-15E jet fighters carried out an airstrike to destroy an ammunition-storage facility, latrines, tents and other parts of the Syria headquarters of the American campaign to destroy Islamic State after pulling its forces from the base.

Col. Myles Caggins, a spokesman for the U.S.-led coalition overseeing the fight against Islamic State, said the airstrikes were intended to “reduce the facility’s military usefulness.”

The decision to target the base, which included warehouses used to train-and-equip the Kurdish-led fighters, came after Turkish-backed forces moved on the facility on Tuesday.

As the Turkish-backed forces moved closer to the LaFarge Cement Factory facility south of Kobane, the Kurdish-backed forces set fire to their part of the base and fled, Col. Caggins said.

The U.S. used Apache helicopters and F-15 jet fighters to intimidate the Turkish-backed fighters and deter them from getting closer to the base, U.S. officials said.

After the show of force, the U.S. military pulled its forces out of the base and carried out what it called a “pre-planned precision airstrike” before Turkish-backed fighters could take control of the facility.