A racist white gang "swallowed" up Stephen Lawrence before he was stabbed to death, the Old Bailey heard.

In the first day of the Stephen Lawrence murder trial, prosecutors told the court that the black 18-year-old was chased by the gang before being surrounded at a bus stop in Eltham, south London.

Gary Dobson, 36, and David Norris, 35, are both accused of murdering Lawrence in the April 1993 attack.

Both deny the charges.

Lawrence was with his friend Duwayne Brooks, who managed to escape, shouting "get up and run, Steve".

"One of the group was heard to say 'What, what nigger?' and at the same time the whole group rushed towards them," said Mark Ellison QC, prosecuting.

"Stephen Lawrence did not manage to get away. The group quickly surrounded him.

"One witness described that he was swallowed up by the weight of numbers and forced to the ground."

Medical evidence suggests Lawrence was stabbed once while standing and once while on the ground, both times in the torso.

He bled to death after two arteries were severed.

Lawrence managed to run 220 yards after being stabbed, before collapsing.

"This group, we allege, looking at the eyewitness evidence, had acted essentially as one. The stab wounds were inflicted and then they had decamped as one up Dickson Road," said Ellison.

Brooks called 999 from a call box before trying to get help from passers by.

A couple and an off-duty police officer driving with his wife stopped to try to help, but Lawrence was showing no signs of life and he died later in hospital.

The court was also shown clothing forming the basis of new evidence, including a grey bomber jacket owned by Dobson and a pair of jeans owned by Norris.

As part of a cold case review in 2007, new scientific techniques unavailable at the time of the original case showed textile fibres, blood and hair linked to Stephen Lawrence on some of the defendants' clothes.

Prosecutors say this is because the men were in the group that killed Lawrence, while the defence says this is from cross-contamination of evidence.

Doreen and Neville Lawrence, Stephen's parents, were both at court for the start of the trial as the twelve jurors were sworn in. Neville Lawrence left shortly after.

Justice Treacy, presiding over the trial, told the jury that the past is "irrelevant" and they must come to a verdict solely on the evidence given in the courtroom.