Two transit buses collided on a downtown street early Monday, sending one bus barreling into the front of a parking garage. Eleven people were injured, two seriously, authorities said.

The crash involved two Metropolitan Transportation Authority buses that collided near the Staples Center about 6 a.m., said Fire Department spokesman Brian Humphrey.

Officials were investigating the circumstances that led to the crash, Humphrey said.

Paramedics treated 11 people, most for minor injuries, Humphrey said. He said at least two people had serious injuries.

MTA spokesman Jose Ubaldo said one bus had no passengers. He didn't know how many people were on the other bus but said nine people were transported to hospitals, including the two drivers. He declined to release further details about the crash.