Updated

Greek authorities say a small civilian helicopter has crashed north of Athens, killing two of the three people on board.

The fire brigade says one of the occupants managed to get out of the wreckage alive before rescuers arrived, while the other two were found unconscious and later pronounced dead by medics.

It was not immediately clear what caused the helicopter to crash Friday into a marsh near Marathon, some 40 kilometers (25 miles) north of Athens.

The fire brigade said it was a privately owned craft that had been chartered by regional authorities, which regularly use helicopters to spray insecticide to control mosquito populations.