A man who saw another man being attacked by a group of youths in Norwich said it was one of the 'worst things' he had ever seen.

The man, who asked to remain anonymous, was walking down King Street when he saw a man being assaulted on Friday night.

He said the victim was left with a bloodied face by a group of "kids" who were wearing hoodies and riding bikes.

He added that, as the youths fled the area they then approached one of his friends and punched him in the face.

Norfolk police confirmed officers are investigating after a man in his 40s was assaulted on King Street at about 10.40pm on July 26.

On Twitter, the witness described the incident as: "one of the worst things I've ever seen".

He said: "Three kids on bikes were fighting one bloke in the distance.

"Now, obviously outnumbering him, I didn't know the back story and [I] was too far away to grasp it.

"The bloke could have been in the wrong, but it didn't look good from a distance."

He said the youths got on their bikes and cycled towards his partner, his friend and himself, while shouting abuse at the man they had attacked.

"As they biked past us, one of the kids landed a punch right on my friend's face."

He said: "He is the nicest, most harmless lad around who didn't say a word. We were in shock."

He said they approached the injured man, who had blood "all over this face".

He said: "He [the man] looks up and says 'I didn't say a word to those boys'."

A police spokesperson said the victim was walking towards the city centre when he was approached by five youths on bikes.

One of the attackers became verbally abusive before punching and kicking the victim, police said.

The victim suffered injuries to his face, but did not require medical treatment at the time.

The witness described the attackers as "cowardly" and "repulsive".

Police confirmed they have made no arrests and enquiries are ongoing.

- Any witnesses should contact police on 101 quoting 36/51784/19.