Crews scouring 7 miles of Southern California beaches scooped up truckloads of mysterious oily goo Thursday and the area might be clean enough to reopen for the weekend, authorities said.

Workers scooped up about 30 cubic yards of tarry balls and patties that began washing ashore Wednesday.

"There appears to be no new tar balls or anything additional to the amount that we have recovered thus far," U.S. Coast Guard Capt. Charlene Downey said.

The stretch of coast from Manhattan Beach to Redondo Beach that was closed to swimmers, surfers and beachgoers could reopen Friday if the sand and sea are given an all-clear, Downey said.

No problems with wildlife had been reported, said Sau Garcia of the California Department of Fish and Wildlife.

U.S. Coast Guard and state officials said samples of tar and water would be analyzed to identify where the material originated, but it could take days to get the results.

There is a refinery and offshore oil tanker terminal nearby but the Coast Guard did not find a sheen from a possible spill after the tar started to accumulate.

Nothing has been ruled out, including a connection to last week's coastal oil spill that created a 10-square-mile slick about 100 miles to the northwest off the Santa Barbara County coast.

Lifeguards chased a handful of surfers out of the water Thursday but beach life was otherwise normal for people exercising, playing volleyball, skating and riding bikes along the shore.

"I got a couple waves in and then they came by again and told me to get out," said Scott Berk, who regularly surfs at Manhattan Beach.

He said surfers are used to seeing bits of tar in the water and on the shore from natural seafloor seepage but the amount that came in Wednesday was concerning.

"I hope they clean it up quickly," he said.

Public health officials told people to avoid contact with the water, wet sand or any material that washed up in the area. They warned that contact with petroleum products can cause skin irritation and result in long-term health problems.

The Associated Press