BEIJING — China's largest reported oil spill had more than doubled by today, closing beaches on the Yellow Sea and prompting an environmental official to warn the sticky black crude posed a "severe threat" to sea life and water quality.

Some workers trying to clean up the inky beaches wore little more than rubber gloves, complicating efforts, one official said. But 40 oil-control boats and hundreds of fishing boats were also deployed in the area.

The oil was spread over 165 square miles of water five days since a pipeline at a busy northeastern port exploded. State media says no more oil is leaking into the sea, but the amount of oil spilled was not clear today. Based on the known figures, the spill is significantly dwarfed by the BP oil spill off the U.S. coast.