A Toronto police officer is expected to make a full recovery after her police cruiser slammed into the side of a TTC bus early Friday, EMS officials say.

The crash occurred at Danforth Avenue and Main Street in Toronto's east end shortly after 1 a.m.

Paramedics rushed the female officer, a sergeant believed to be in her 40s, to St. Michael's Hospital on an emergency run, but her injuries weren't as severe as initially feared.

Police said the woman suffered an injury to her ankle. No one on the bus was injured.

It's believed the collision occurred when the officer was responding to a call for assistance after a man ran away from a fellow officer.

The woman's eastbound police cruiser crashed into the rear doors of a TTC bus, which was crossing Danforth Avenue as it travelled south on Main Street. The cruiser sustained significant damage to its front end.

A witness told CP24 the police cruiser had a red light, while the bus had the green light. Emergency vehicles are permitted to go through red lights and stop signs if the vehicle's emergency equipment, such as flashing lights, is activated.

Police are investigating the collision.

The intersection was shut down for several hours.