Coast Guard: Fuel oil was substance that spilled in Potomac

ARLINGTON, Va. (AP) -- Authorities say initial tests show that fuel oil is what spilled into the Potomac River near Reagan National Airport last week.

U.S. Coast Guard Cmdr. Michael Keane said Monday at a news conference that authorities are still waiting for test results on additional samples. The source of the spill has not been found, and Keane says it's possible it never will be.

Keane says the oil sheens have mostly dissipated. The oil was spotted in the water last Wednesday. He says the spill was "fairly minor" and that the Coast Guard is working to minimize the environmental impact.

The number of oiled birds being cared for at an animal-rescue facility now stands at 30.