The 3,000-barrel spill has created an oil slick plume stretching 5.8 nautical miles, from Huntington Beach Pier to Newport Beach, the statement said. City officials have asked people to stay off the beaches. Crews led by the U.S. Coast Guard are working on the cleanup.

The spill was likely caused by a ruptured pipeline connected to an offshore oil platform known as Elly that is operated by Beta Operating Co., Orange County Supervisor Katrina Foley said on Twitter. Officials from Amplify Energy Corp., the parent of Beta, didn’t respond to a request for comment from Bloomberg.