A murder inquiry was under way today after a man died of injuries inflicted during a suspected homophobic attack.
Ian Baynham, 62, suffered fatal head injuries in an assault close to the South African High Commission, in Trafalgar Square, central London.
He died in hospital last night when doctors switched off his life support machine, more than a fortnight after the attack on September 25.
Police want to trace three young people, including two teenage girls who were caught on CCTV, seen in the area.
Mr Baynham, from Beckenham, south east London, suffered severe brain damage when he was punched and kicked to the ground. His attackers shouted homophobic abuse.
He was on his way to a night out in the West End with a 30-year-old friend when the attack took place shortly before 11pm.
The two men had just got off a number 24 bus in Duncannon Street when three youths confronted them and shouted abuse. The friend was treated for minor injuries.
Detectives from Scotland Yard's Homicide and Serious Crime Command are investigating the murder.
They want the public to help them identify the two girls who may have been sitting in the square with a dark-skinned male youth earlier that evening.
Investigators said the three, all aged between 16 and 20, are suspected of shouting verbal abuse at other people as well.
In July, Commissioner Sir Paul Stephenson highlighted his concerns over how the number of homophobic crimes in the capital was increasing.
He said the force's response to such crimes was "light years" ahead of what it was in the past, and victims were more willing to report offences.
Senior officers were told homophobic crimes have increased by almost 14%, an extra 39 offences, since April, and there has also been an increase nationally.
There have been three other suspected homophobic murders in the capital over the past year.
In July, 79-year-old Edward Highwood was murdered at his home in Hollymount Close, Greenwich. Neighbours and friends feared he was targeted because he was gay.
Gerry Edwards, 59, was stabbed to death at his flat in Bromley, south east London, in March. His partner also suffered stab wounds.
In November 2008, David Cooper, 28, was beaten to death at his flat in Calderwood Street, Woolwich. He had been drinking in Soho the night before his murder.
Councillor Daniel Astaire, of Westminster City Council, said he is "extremely concerned" by the attack.
He said: "While such incidents are extremely rare in Westminster, we do not tolerate any violence or homophobia of any kind.
"We will offer any support we can to the police to help catch those responsible, and work with the local community to help prevent any such attack occurring again.
"We are incredibly proud of Soho's vibrant gay community, which welcomes visitors from around the world and is an essential part of the area's rich heritage.
"We are confident the local community will rally round and not be intimidated by this mindless, abhorrent act of violence which tragically resulted in an innocent man losing his life.
"Their safety is of paramount importance to both the police and council, and we would urge anybody who has any information which could help, no matter how small or apparently inconsequential, to contact the police."
Anyone with information, or who recognises the two young women in the CCTV images, should call 0207 321 9314 or Crimestoppers on 0800 555 111.