Imperial Oil Ltd. says it has stopped production at its Kearl oilsands mining operation in northern Alberta because of the partial shutdown of the Polaris diluent pipeline following a spill near Fort McMurray.

The company is in contact with its customers but has not yet identified the cause of the leak.

A Chinese-owned company has been fined after a contractor's mistake led to a pipeline spill that contaminated a creek flowing into the Athabasca River in northern Alberta.