Hundreds of firefighters were dispatched to two separate blazes just blocks apart in Montreal Friday, and officials say at least three people have been hospitalized.

The first fire broke out just before 5 p.m. on the 30th floor of the Bell Media Tower on McGill College Avenue at Sainte-Catherine Street. A second blaze erupted just a few blocks away at McGill University’s McIntyre Medical Building sometime after 8 p.m.

The causes of both fires remain unclear. Officials have given no indication that they are connected.

About 200 firefighters responded to the Bell Media Tower fire. Firefighter Francis Leduc told CTV Montreal that four workers near the top of the building were treated on the scene. Three others were transported to hospital.

“We evacuated the building right away,” Leduc said.

“The building itself became full of smoke so it made it a bit tougher to get the people out,” he added. “It’s even tougher for us (because) we have to go by the staircase.”

Montreal’s fire department said on Twitter around 5:30 p.m. local time that the fire had grown to a five-alarm blaze. They asked that people avoid the area.

Montreal fire officials confirmed the McGill University blaze at 8:41 p.m. on Twitter. At the time, the blaze was reported as a third-alarm fire.

Images from the scene show thick plumes of black smoke pouring from the medical building’s roof.