Four passengers suffered minor injuries early Saturday after an AC Transit bus driver sped away from gunfire that blew out the back window of a bus, AC Transit officials said.

The articulated Line 1 bus was northbound on International Boulevard near 55th Avenue in Oakland about 12:20 a.m. with nine passengers aboard when it was hit with five to seven shots that shattered the rear window, said Clarence Johnson, an AC Transit spokesman. No one was injured by the gunfire. The driver, as trained, immediately accelerated to get to a safer location, Johnson said. Four passengers who said they were injured when the bus suddenly sped up were taken to the hospital.