Halifax Regional Municipality has softened its stance on the ban against barrel fires, which striking transit workers have been using to keep warm on the picket line.

On Friday, the municipality said it would begin enforcing the bylaw banning the fires, but it seemed to back down Saturday, when a handful of Metro Transit workers stood around a barrel fire to combat the cold of the latest storm. Strong winds blew ash from the fire into the air.

Metro Transit strikers stay warm and cook food using fires in barrels. (CBC)

Pickets have been using barrel fires to keep warm and cook food, and until Friday, the municipality had shown no signs of stopping them. The fine for open-air burning is a minimum $250.

Workers declined to comment, but city spokesperson Shaune MacKinlay said HRM struck a compromise with the union.

"We're just taking a measured approach," MacKinlay said. "We've sent our fire crews out, we've monitored the situation. There are times when we've had to have the people who lit the fires extinguish it or we've had our fire crews extinguish it."

She said the municipality reserves the right to extinguish the fires, "but if they keep the fires lower than the top of barrel that will help address risk."

MacKinlay said the bylaw gives discretion to the property owner, which in this case is HRM.

"We can allow it on our property, but we've been monitoring the situation since the strike began."

The length of the strike is a factor in the municipality's reaction to the fires.

"We're going into our fourth week here. We will be taking an approach, where if we're getting 911 calls about those burn barrels, we'll extinguish the fires."

Transit strikers returned to the picket lines Friday after rejecting the city's latest offer, with 78 per cent voting against it. No further talks are scheduled.