A number of people are feared dead after a helicopter crash in the Mourne Mountains in County Down on Saturday afternoon.
It is not known how many people were on board but local MLA Jim Wells said he believed that several had been killed.
He added that it happened in an area known locally as Leitrim Lodge between Hilltown and Rostrevor.
The aircraft is believed to have left St Angelo Airport in Enniskillen earlier on Saturday.
It is understood to be a medium-sized Agusta helicopter capable or carrying up to eight people.
Eyewitnesses first reported an aircraft in distress in the Mournes at about 1600 BST.
Police are leading the operation assisted by the Mourne Mountain Rescue Team, the Fire and Rescue Service and the Ambulance Service.
Keiron Tourish, reporting for the BBC from the scene, said a picnic area at Leitrim Lodge had been cordoned off.
A police spokesperson said that the Air Accidents Investigation Branch had been informed.
BBC News
