Barrie police are looking for two people in connection with a suspicious fire at a downtown apartment building.

Firefighters used a ladder to rescue a woman trapped on the third floor of the building at 68 Mary Street on Friday afternoon.

She was treated in hospital for minor injuries and released.

Police could not offer a detailed description of the people they're looking for, saying only that they were wearing dark jackets and were walking on Mary Street between 1:15 p.m. and 1:45 p.m. Investigators did not specify if these people are suspects or persons of interest.

The Ontario Fire Marshal's office is helping with the investigation.

There were reports of an explosion, but the fire chief says there was no evidence of a blast.

Residents of the building's third floor were not able to sleep at home Friday night. It is not clear how long they may be displaced.