Several buildings in downtown Hay River, N.W.T., have been evacuated because of an ammonia leak at a demolition site.

The leak is at Hay River's recreation centre, which is being torn down. It was caused by a worker using a reciprocating saw on the site, according to a news release from the Town of Hay River.

"The fire department's going around and telling people to leave buildings downtown," said Jane Groenewegen, a former MLA who owns the local Driftwood Diner.

"I was in the building and we could smell it really strong in there because we were right across the street from where it was leaking," she said.

The downtown core has been cordoned off.

The Godwin Mall, the aquatic centre, Northmart, the Source and the Driftwood Diner have all been evacuated.

Ruth Boden, Hay River's acting senior administrative officer, says the buildings are expected to remain closed for the better part of the day. She says the leak is under control but it's expected to continue draining for the next three to five hours.