The Chief Constable last night led tributes to “four fine officers” who were killed in a horrific car accident as they responded to calls for help from a colleague.

Their 4x4 vehicle hit a wall and burst into flames on a stretch of coast road in south Co Down shortly before 4am yesterday. The two full-time and two part-time policemen were responding to a request for assistance from another officer.

There was no evidence of a terrorist link to the crash which happened on the main Warrenpoint to Rostrevor road and no other vehicles were involved.

It is the force’s biggest single loss of life since the terrorist ceasefires.

They were part-time officers 39-year-old Declan Greene, who lost three relatives in the Tullymurray Lass trawler tragedy in 2002, and 30-year-old Kenny Irvine, who is understood to be from Mourneview Close in Kilkeel and the father of a young baby.

Full-time officers Kevin Gorman (24) and 27-year-old James Magee, both believed to be from the south Down area, were also killed.

The Ulster Unionist Party's Basil McCrea said he was shocked to hear of the tragedy and he extended his condolences to the deceased officers' families, friends and colleagues.

"This is a dreadful tragedy," he said, "And it is a stark reminder of the debt we owe the PSNI for the work they do for the community.

"The Ulster Unionist Party passes on its sincere condolences."

Mr McCrea, a member of the Northern Ireland Policing Board, said the fact that the accident came only weeks before Christmas made the circumstances all the more tragic.

The Kilkeel police station is closed on weekends and it is understood officers travelled from Newry to carry out routine inquiries, most often related to alcohol-related complaints.

Democratic Unionist Party (DUP) Assembly member Jim Wells who represents the area said the accident was a devastating tragedy.

"Everyone in the Mourne community will know one or other of these men," he said.

"This will be a dreadful tragedy for the entire community and it will take a long time for people to come to terms with what has happened."

He extended his condolences to the families of those involved in the accident, which is believed to have taken place when driving conditions were poor.

Mr Wells said: "It is important that we find out the circumstances behind this tragedy and make certain all necessary steps are taken to ensure there is no recurrence."

Mr Wells added: "This is a most tragic accident where four families have been plunged into grief. It is my prayer that the peace of God will be with each family as they face this difficult time."

PSNI Chief Constable Sir Hugh Orde arrived at the scene of the accident yesterday morning.

The deaths represent the largest loss of life to hit the police service since republican and loyalist groups went on ceasefire more than a decade ago.

Northern Ireland Secretary of State Shaun Woodward said: "The deaths of four police officers in this terrible road accident when responding to a call is a profound tragedy for their families and the PSNI.

"I want to extend my deepest sympathy to their loved ones and their friends and colleagues who served with them.

"The police do difficult and often dangerous work to protect the community and keep it safe.

"It is at times like this that the huge debt that we all owe them is brought home in a particularly shocking and cruel way."

Two men and a woman died in separate road accidents around Northern Ireland over the weekend and Environment Minister Sammy Wilson extended his sympathies to all those who had lost their lives.

"This has been one of the worst weekends on the roads in Northern Ireland," he said.

"Our thoughts are with the families of the three people who died in accidents on Friday and the four PSNI officers killed.

"It is especially hard on any family to lose a loved one in the run-up to Christmas. They will need relatives, friends and neighbours to rally around them at this difficult time.

"I also would like to extend my and my Department's condolences to Chief Constable Sir Hugh Orde, senior officers and colleagues of the four PSNI officers killed in last night's crash in Co Down while on duty. They will also be feeling a deep sense of loss.

"Although the full details of these accidents have not emerged, what these deaths demonstrate is the need for everyone to be alert to dangers on the road - especially at this time of year."

Chairman of the Policing Board Professor Sir Desmond Rea said: "To lose four officers in a road traffic collision is horrific and on behalf of the Policing Board I offer my sincere condolences to the families of these officers who will be absolutely devastated by this tragic event.

"This is also a huge loss for the PSNI and I send my condolences to the Chief Constable, Sir Hugh Orde, Judith Gillespie, ACC Rural, and Chief Superintendent Alan Todd, E District Commander, on the deaths of four of their officers.

"The colleagues of these officers will also be deeply affected by this tragedy, particularly those who worked alongside them in the Newry and Mourne District, and I also extend my deepest sympathy to them."

South Down Ulster Unionist Party MLA John McCallister also conveyed his deepest sympathies.

“I was shocked and deeply saddened when the news came through of this devastating tragedy, and I would like to extend my deepest sympathies to the officers’ loved ones, as well as their friends and colleagues who served with them.

"This distressing news will be felt across South Down and further afield, as these young men were well known and gave so much to the community,” said Mr McCallister

He added: “These young men were out serving our community, and just doing their job to the best of their ability. This just makes the tragedy even more difficult to comprehend. It brings home the message that all too often we are hearing the tragic tale of too many fatalities on our roads.”