A have-a-go-hero was attacked as he went to the aid of a screaming woman who was being dragged along a Brighton street.

The 18-year-old was walking in Bloomsbury Place, Brighton, at 8pm on Sunday when he saw a woman screaming and being dragged by a man.

When the teenager asked the woman if she was ok, the man with her pulled out a knife and slashed him across the hand and forearm.

The victim punched the man to push him away and then ran home and called police.

The man was white, about 20 and slim. He was wearing a blue hooded top and a grey tracksuit or trousers.

The woman was white and slim. She had blonde hair and was wearing a dark hooded top and cut off jeans.

Detective Constable Shirley White said: "This was a nasty attack on a teenager who was trying to do the right thing when he saw a woman in distress.

"I need to speak to anyone who was in the area at about 8pm on Sunday and saw or heard the incident or what happened next.

"If you know anything at all about those who were involved, please contact me."

Call Sussex Police on 101.