Two suspected militants went on trial in Northern Ireland on Monday charged with the murder of two British soldiers outside an army base in 2009, in one of the worst attacks since a 1998 peace deal mostly ended three decades of sectarian violence.

The killings were claimed by the Real IRA, a dissident group opposed to the Irish Republican Army ending its campaign against British rule.

Colin Duffy, 43, from county Armagh and Brian Shivers, 45, of county Londonderry -- both areas with dissident activity -- deny murdering soldiers Patrick Azimkar and Mark Quinsey.

Azimkar, 21, and Quinsey, 23, were shot dead outside the Massereene Barracks in Antrim as they collected a pizza just hours before they were due to fly out to Afghanistan. Four other people were seriously injured, including the pizza delivery men.

CCTV footage aired in court showed the soldiers trying to escape from the gunfire. Two figures dressed in black and wearing balaclavas paused after the first onslaught and then resumed firing.

Chillingly, the gunmen moved forward to shoot the soldiers on the ground to ensure they were killed, prosecuting lawyer Terence Mooney told a packed courthouse, a short distance from the murder scene.

Members of the soldiers' families left the room while the footage was shown.

The green Vauxhall car used by the killers was found abandoned seven miles away from the army base. An attempt to torch the vehicle was only partially successful and the prosecution case alleges it provided DNA links to the accused.

DNA matching Duffy was alleged to have been found on the tip of a rubber glove found in the vehicle, prosecutors have said.

Duffy and Shivers deny the murder charges, as well as other charges of attempted murder and possession of firearms.

Almost 200 witnesses will give evidence during the trial, one of the most high profile in Northern Ireland in years. It is expected to last several weeks.

The Real IRA was behind the worst attack of the decades of violence when a car bomb killed 29 people including several children and a woman pregnant with twins in 1998.

The peace deal largely ended the conflict in Northern Ireland that cost some 3,600 lives, but there has been an upsurge of shootings and bombings in recent years.

A bomb exploded at a civic office in the centre of Londonderry last month while a policeman was killed when a bomb exploded under his car in April.

(Reporting by Ian Graham; Editing by Padraic Halpin)