US coast guard investigates Los Angeles oil spill

The spill is located close to two oil rigs off the shore of Huntington Beach, a popular beach city known for its world-famous surfing, but the source is not yet known, the Coast Guard said in a statement.

"The Coast Guard is contacting all potential spill sources in the area, but no source has been identified," it said.

Authorities are "working to identify possible impacts to the shoreline and environmental protection strategies" but so far "no oiled wildlife has been observed," the statement said.

The spill was first spotted on Thursday night but was initially suspected to be a sewage release, said California's wildlife department.

But "an overflight this morning observed oil sheen. More info to come," said the department's office of spill prevention and response.

The coast guard said a patrol boat and helicopter has ascertained the sheen was currently 2.5 miles long, and half a mile wide.

The city of Huntington Beach has not yet ordered any beaches to be closed.

In 2021, a cracked pipeline leaked an estimated 25,000 gallons of crude oil onto beaches in the area south of Los Angeles.

The waters are home to wildlife including whales, dolphins and otters.