Ontario's air ambulance service is confirming four of its employees have died after one of its helicopters crashed in northern Ontario.

The Ornge air ambulance service says no one survived the accident near Moosonee, Ontario early Friday.

Ornge says two pilots and two paramedics were on board the aircraft, but no patients.

The air ambulance service says it lost contact with the Sikorsky S76 shortly after takeoff from its base in Moosonee around midnight.

Canada's Transportation Safety Board has been notified and will be investigating the cause.