A dozen killer whales are trapped under a vast stretch of sea ice in northern Canada, while officials try to work out a way to free them.

Locals in Inukjuak, in the far north of Quebec, said the mammals have gathered around a car-sized hole in the ice to get oxygen.

A dozen killer whales have been trapped by sea ice in northern Canada. Credit:AP/Marina Lacasse

Mayor Peter Inukpuk urged the Canadian government on Wednesday to send an icebreaker as soon as possible to crack open the ice and help them find open water.

The Department of Fisheries and Oceans said it is sending officials to assess the problem.