Crews have suspened work cleaning up an oil spill that washed up on three miles of shoreline from Long Beach and Atlantic Beach.

The U.S. Coast Guard is still uncertain about the source of the spill -- saying it likely came from a passing ship.

The Coast Guard said it is working with local, state and federal agencies to clean up the spill, which closed Atlantic beach Friday.

About 500 gallons of no. 6 oil--an industrial oil—spilled along the shoreline, officials said.

Surfers called in Thursday about the slick.

So far, only several birds were reported affected by the oil.