Oil from a ruptured underwater pipeline washed up on some of Southern California's most popular beaches Monday.

More than 27,000 gallons of a mixture of diesel oil and jet fuel leaked into the Pacific after a ship's anchor punctured the Chevron refinery pipeline 60 feet underwater Saturday night.Oil began washing ashore at Topanga and Malibu beaches late Sunday. Malibu, popular with surfers and swimmers, is home to a number of celebrities.

A storm expected to bring strong winds and rain Monday was likely to push more oil onto shore, said Coast Guard Lt. Mike Miles.

Thirteen skimmers and boom-towing boats were sent to contain the spill on Sunday, but Chevron spokesman Tom Richart said they weren't doing much good because the fuel was light and couldn't be as easily scooped up as heavy crude.

The Coast Guard said the cleanup had been suspended until dawn.

The spill created an almost transparent slick 4.5 miles long and 2.5 miles wide. It had traveled as far as 20 miles north, from the refinery in El Segundo to Malibu, by early Monday.

The spill closed bustling Marina del Rey, home to more than 6,000 pleasure boats, when booms were set up across the harbor entrance to keep oil from reaching the ecologically sensitive Ballona Wetlands.

The impact on marine life wasn't immediately clear, but Lt. Reed Smith of the state Department of Fish and Game said many sea lions and dolphins live in the spill area. Four oil-soaked birds were rescued.

"Chevron is taking full responsibility for coordinating the cleanup effort and we are focusing our resources on minimizing any adverse impact," said Will Price, president of San Francisco-based Chevron USA Inc.

The spill occurred about a mile offshore from the Chevron refinery in El Segundo, which is about 15 miles southwest of Los Angeles.

Mike Holmes, the refinery's general manager, said the 610-foot, U.S.-flagged tanker OMI Dynachem was backing into a berth at a mooring offshore when its crew decided to abort the docking because of a damaged winch. The winch is used to pull the ship alongside the berth by cable.

The ship's anchor then struck and pierced the 26-inch pipeline, Holmes said. The ship, carrying solvent used in gasoline, was not damaged.

The tanker's four crew members and Chevron's mooring pilot tested negative for alcohol, said Coast Guard Capt. Jim Morris. He said drug tests would also be conducted.