Surrounded by a group of Hells Angels members at a First Street gas station

Dozen police cars arrived after a man reported being tipped off his bike on Interstate 580 and then being surrounded by a group of Hells Angels members at a First Street gas station near the I-580 off-ramp.The man, whose city of residence and age were not released, told officers he was exiting the freeway at First Street about 3 p.m. when a rider in a group of bikers pulled up and told him to get behind them, Bye said. The man told police that when he didn't drop back, he was run off the road.The riders then pulled into the gas station and got into an argument. The man called police, saying he was surrounded, Bye said. Twelve people were detained at the scene. Two were arrested for weapons violations and another for the altercation.Bye said the lone biker suffered a bruised knee and was the only one injured.