At least 15 people were injured Saturday, two with possibly life-threatening injuries, after a bus collided with two civilian vehicles in Baltimore, according to Baltimore City Police.

"Approximately 10-15 individuals were transported to local hospitals. The extent of their injuries is unknown," Maryland Transit Administration spokesperson Jerimiah Moerke told CNN. "Maryland Transit Administration Police continue to actively investigate the incident.

Police told CNN the MTA bus collided with a Lexus at North Paca Street at West Mulberry Street Saturday morning. The bus then struck a Nissan and came to a stop resting in a building at 500 West Franklin Street, police said.

Baltimore City Police said the cause of the crash is unknown at this time.

Moerke told CNN the agency's CityLink Blue bus was "involved in a multi-vehicle incident" at around 10.15 a.m.

MTA Police, the Baltimore City Fire Department and Medics, and building inspectors are also on the scene, police said.

Video from CNN affiliate WJZ shows the bus at a stop against the side of the building with smashed out windows as emergency services respond.