Halifax Regional Police have reopened the streets around the scene of a natural gas leak in the city's downtown that officers say was caused by a snowplow clipping a line.

Emergency crews were called to the Centennial Building on Granville Street just before 4:30 p.m. on Wednesday.

Traffic was closed to the area bordered by Argyle Street, Lower Water Street, Sackville Street and George Street and police urged motorists and pedestrians to avoid the area.

Crews were purging the gas line before capping it.

Judy Myrden, managing editor of business news website allnovascotia.com, was in the Centennial Building on Wednesday afternoon. She said she learned of the gas leak was when her husband, CBC reporter Paul Withers, called to tell her.

"There were no alarms, nobody had come to the door to tell me what had been going on," Myrden said.

The elevators were shut down and Myrden said she used the stairs to leave the building. When she emerged the place was surrounded by police cars.

Centennial Building

The Centennial Building on Granville Street in Halifax (Google)