A ruptured fuel line on a Panamanian-registered tanker released oil into San Francisco Bay before dawn on Friday, authorities said.

The US Coast Guard said the source of Friday's spill, from the tanker Dubai Star, was contained within hours and that a cleanup was under way. It was not immediately clear how much fuel had spilled.

Coast Guard officials said the spill of the heavy bunker oil occurred during fueling operations between the Dubai Star and a barge. It occurred near the Oakland Airport, across the bay from San Francisco.

The spill occurred almost two years after the Cosco Busan tanker struck the San Francisco-Oakland Bay Bridge in 2007, which led 53,000 gallons of bunker fuel being dumped into the bay.

The spill created a massive fuel slick that washed up on beaches in the bay and along the Pacific coast. Thousands of marine birds were killed by that spill, and officials estimated the cost of clean-up at 70 million dollars.

(c) 2009 AFP