UK coast guard said that all 18 people aboard the helicopter that ditched in North Sea are rescued.
Maritime and Coastguard Agency spokesman Mark Clark said the helicopter "ditched" as it approached an oil installation 190 kilometers east of the Scottish city of Aberdeen.
The BBC identified the aircraft as a "Super Puma" transport helicopter and said it was headed for an oil rig in the area. It said three helicopters had been dispatched to the scene.
Clark said he could offer no further detail on the nature of the incident or say whether there had been any casualties.
British military spokesman James Lyne told the BBC the helicopter would have been equipped with life jackets, which carry electronic transmitters.