YORKTOWN, Va. (AP) — A large warship spilled 4,000 gallons of fuel into a Virginia river late last week, the U.S. Navy has confirmed.

The USS Philippine Sea, a guided-missile cruiser, spilled the diesel fuel into the York River on Thursday morning, WAVY-TV reported Monday.

The ship was at a pier at the Naval Weapons Station in Yorktown at the time, according to Ted Brown, a U.S. Fleet Forces Command Environmental Public Affairs Officer.

A Navy oil recovery team and the U.S. Coast Guard responded, and most of the fuel was contained, officials said. Cleanup efforts began immediately using a fuel vacuum truck and fuel-absorbing materials, Brown added. He said there was little impact to the shoreline.

The Navy is investigating the cause of the spill.