At about 11:35 a.m., a 77X bus, taking commuters to the 49ers game at Candlestick Park, was involved in a collision with two other vehicles, said Muni spokesman Judson True.
The bus then struck a tree and pole, according to True.
Employees at Tommy's Joynt, a restaurant at the intersection, said they heard the collision.
"It sounded like a lot of weight slamming into something very heavy," said Sam Katzman, assistant manger of the restaurant.
True said the operator and five passengers on the bus were taken to the hospital.
The injuries were described as non-life-threatening by the fire department, according to True.
The driver of the bus will be put on non-driving status and tested for drugs and alcohol as part of standard Muni procedure, True said.
San Francisco police will invest the official cause of the collision.