By Steve Gorman

LOS ANGELES (Reuters) - At least some of the tar balls found littering one of southern California's most popular beaches last month were matched by lab tests to crude oil that spilled from a ruptured pipeline along the Santa Barbara coast about 100 miles away, state and pipeline company officials said on Monday.

Sticky, black oil globs began washing up along more than 6 miles of Manhattan Beach, just southwest of Los Angeles on May 27, prompting health officials to briefly close a stretch of shoreline in the area.

Another stretch of coast was placed off-limits to the public in Long Beach a week later after a wave of tar balls washed up there, and swarms of oil blobs have come ashore as away as San Clemente in Orange County, about 60 miles farther south.

Nine tar samples were collected from in and around Manhattan Beach, and chemical analysis shows two were consistent with oil spilled on May 19 from the failed pipeline operated by Plains All American Pipeline, the company said.

Six other samples were consistent with oil seeping from naturally occurring fissures in the seabed along the Santa Barbara coastline, while tests from three remaining samples have yet to yet to be completed, Plains said in a statement.

The tar ball "fingerprint" analysis was conducted by scientists from the Woods Hole Oceanographic Institution in Massachusetts and the University of California at Santa Barbara, Plains spokeswoman Meredith Matthews said.

Separately, the California Department of Fish and Wildlife reported on Monday that its own analysis of a Manhattan Beach tar ball sample showed a match with the Santa Barbara spill.

More than 50 samples in all have been collected by Plains from oil blobs along the California coast since the pipeline breach, and initial findings from up and down the coast indicate a mix of oil from the spill and natural seepage, Plains said.

Patrick Sullivan of the environmental group Center for Biological Diversity said the results "suggest that the damage from the oil spill extends quite a bit farther than anyone would have guessed."

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The pipeline break west of Santa Barbara dumped as much as 2,400 barrels of crude onto a pristine beach and into the Pacific, leaving an oil slick that stretched over 9 miles.

Nearly 250 petroleum-stained sea birds have been recovered dead and alive since then, along with over 260 marine mammals suspected of being spill casualties, according to a running tally kept by wildlife officials.

(Reporting by Steve Gorman; Editing by Michael Perry)