US news channel, CBS, is reporting on a fire that broke out in the middle of the night at the Apple R&D facility in Cupertino.

Up to 66 fighters were reported to be on the scene to combat the fire that workers reported to be on the roof of the building.

Early assesment from firefighter deputy Rooney, who gave a briefing to the press, revealed that the fire started under an air conditioning unit.

The firefighters were busy trying to clear the smoke from the building before checking whether any kit in the facility had been damaged by water.

No one was reported to be in the building when the fire broke out.