An investigation is under way after four policemen died in Northern Ireland when their vehicle hit a wall and burst into flames.

An investigation is under way after four policemen died in Northern Ireland when their vehicle hit a wall and burst into flames.

The officers were from the County Down area and died when their Shogun 4x4 crashed on a coastal road between Kilkeel and Warrenpoint shortly before 4am yesterday.

Chief Constable Sir Hugh Orde led tributes to the men, who were aged in their mid-20s to mid-30s.

There were no other vehicles involved in the crash and a senior officer will investigate the tragedy, including claims that a member of the public made a desperate bid to rescue the men.

The two full-time and two part-time officers have yet to be identified, but one who was named locally as Declan Greene lost three members of his family in a County Down fishing tragedy six years ago.

Sir Hugh said: "This is an extremely sad day for the family, friends and colleagues who served with the police officers who lost their lives in this tragic incident in the early hours of this morning.

"The police family have lost four fine police officers in what are deeply tragic circumstances and our heartfelt condolences go out to their families."

A "black box" recorder in the police vehicle will be key to uncovering what happened and police said they will investigate unconfirmed reports that the blaze set off ammunition in the car.

Police have ruled out speculation that the men had been trapped in the vehicle by a locking system.

In 2002 three members of the Greene family - eight-year-old Michael and his father and grandfather who were also called Michael - died when their fishing vessel, the Tullaghmurry Lass, sank off the County Down coast.

Last night a priest from the area, Father Michael Murray, said that Mr Greene was a nephew of the eldest of the three family members to die in the fishing tragedy.