A gay man allegedly attacked in Trafalgar Square by a gang including a girl from East Sussex was hit with a handbag before being knocked to the ground, a court heard.

Ian Baynham had grabbed the bag and struck the girl who hit him back with it before a youth ran over and felled him with a single blow, said witness Robert Fletcher.

After striking 62-year-old Mr Baynham with a "running punch" the youth said "you can't hit girls", Mr Fletcher told an Old Bailey jury.

He said the blonde girl who had been hitting him with the bag and another female then kicked him while he was on the ground.

The first girl delivered the blows "with the total force she could deliver considering she was a slight girl with stiletto-heeled shoes on", he said.

Mr Baynham died 18 days after the alleged attack in central London in September last year.

Joel Alexander, 19, of Thornton Heath, south London, Rachel Burke, 18, of Three Oaks, East Sussex, and Ruby Thomas, 18, of Lichfield, Staffs, deny manslaughter.

Mr Fletcher said the first thing he saw of the incident was a girl wearing a short skirt and stilettos "hitting a guy with her handbag". He said she struck him twice before he "grabbed the bag and then hit her back with it".

"As he hit her with the bag, that was when the young black guy came over and hit the old man," he said. "He just gave one big punch to the old man and that was it, one hit and then the man went on the floor.

The trial was adjourned until next week.