The two girls being sought by police for the murder of 62-year-old gay man Ian Baynham had been screaming homophobic abuse at him before they kicked him to death.

Police said today that Baynham, who was out celebrating a new job as a civil servant, was right to confront the two girls and a boy before the attack in Trafalgar Square.

The incident happened on September 25th. Baynham suffered head injuries and his life support machine was switched off on Tuesday night. Police have launched a manhunt for his attackers.

Detective chief inspector Clive Heys told the Evening Standard that Baynham, of Beckenham, Kent, had recently won a job at the UK Border Agency after a long period out of work. He had also qualified as a counsellor for AIDS sufferers.

He added: “I don’t criticise Mr Baynham in any way for his actions.

“If you are 62 years of age and minding your own business when somebody hurls abuse at you, I think you are entitled to remonstrate with them. It is horrendous that this can happen in Trafalgar Square on a Friday night. It would appear to be completely random.”

The attack happened at 10.45pm on the Friday night. Baynham and a 30-year-old male friend got off the number 24 bus on Duncannon Street and walked into Trafalgar Square, which was full of people. The three youths were sitting on a wall outside South Africa House and were reportedly shouting obscenities at other passersby. One of the girls screamed homophobic abuse at the victim and his friend.

Police say that after confronting the youths about their behaviour, Baynham was knocked to the floor by a punch from the boy. One or both of the girls then began kicking him.

It has been reported that Baynham’s friend grabbed one of the girls as she tried to flee after the attack but was forced to let her go when a well-meaning passerby assumed he was assaulting her.

CCTV images of the two girls have been released. They have been described as having blonde hair and both were wearing jeans. The boy was described as dark-skinned. All were aged between 16 and 20.

Anyone with information should call Crimestoppers on 0800 555 111.

There have been a number of homophobic murders in the capital in the last 12 months.

In July, Edward Highwood, 79, was found murdered at his home in Greenwich.

Gerry Edwards, 59, was stabbed to death at his home in Bromley in March, while his partner suffered serious stab wounds.

In November last year, David Cooper was beaten to death at his home in Woolwich.