Crews are working to contain a fuel leak in San Francisco Bay after an oil tanker spilled hundreds of gallons into the water, creating a slick at least a mile long.

Coast Guard officials say a fuel line ruptured during a fuel transfer on the Panamanian-flagged Dubai Star early Friday morning. The spill happened about 2 1/2 miles southeast of the San Francisco-Oakland Bay Bridge, and officials say none of the fuel has made it to shore.

Mayor Gavin Newsom says booms were quickly deployed to contain the oil slick and additional booms are protecting Treasure Island and Yerba Buena Island.

A nonprofit specializing in oil-spill cleanup is helping at the scene.