DONKIN, N.S. - Nova Scotia's Labour Department has lifted a stop-work order imposed on a Cape Breton coal mine after a methane fire broke out Tuesday afternoon on one rock face.

Harold Carroll, the provincial Labour Department's executive director of occupational health and safety, said today the fire was caused by a mining machine striking a rock, causing sparks that ignited a small pool of methane.

He says the ignition was extinguished rapidly and no safety issues have been identified. In fact, he says the incident suggests the Donkin mine's ventilation system is working well, and the miners responded rapidly to the problem.

The stop-work order issued Wednesday was applied to a 730-metre rock face that the Labour Department had permitted to reopen in January after a series of roof collapses.

Both the company and Carroll say it's normal that mining machines will cause sparks and that there will be emissions of methane, but they say measures are in place to dampen the sparks and create ventilation at the rock face.

The mine, which runs deep under the Atlantic Ocean off Cape Breton's north shore, has received 16 fines for a variety of safety infractions since October 2017.