The Canadian Coast Gurad is patrolling a portion of lower Lake Huron to help its U.S. counterpart in the cleanup of a fuel leak from a barge and tugboat which sank in the area.

The U.S. Coast Guard says air crews spotted an oil sheen on Saturday during salvage operations for a barge and tugboat that sank Thursday in rough weather.

The vessels went down about one and a half kilometres from Lakeport, Mich., releasing some of the fuel on board.

The Canadian Coast Guard says the spill remained in u.s. waters and isn't expected to reach the Canadian side.