A man pretending to be a firefighter tied up emergency crews after he persuaded several businesses in Dartmouth to activate their own fire alarms, according to Halifax Regional Police. 

"It puts everybody's lives in jeopardy because you have emergency vehicles responding and now these vehicles are taken out of service to respond to actual calls if needed. So it's a pretty serious offence," said Staff Sgt. Bill Morris.

Morris said the calls started around 3:20 p.m. Saturday, and after two hours seven businesses in Dartmouth were called.   

All of the calls came from a man who identified himself as a firefighter and asked business owners or employees to pull their fire alarm as a test, he said. 

Each time firefighters and police responded with several crews. 

"It was a hoax. We have no idea who this person was, or why they were doing it, but it is a crime what they did and it tied up several emergency services," said Morris.  

"We're hoping that somebody in the community or somebody may know something about it and could give us a call and help us find this person." 

Police are still searching for the man who made the calls. Morris said the fire department does not call businesses to test fire alarms.