Two teenagers were threatened with a knife and attacked during a robbery in a Norwich park with one of the victim's being knocked unconscious.

The victims, both aged 19, were approached by three males and a female, at Sloughbottom Park on the meadow area of Marriotts Way, near to the River Wensum and Swanton Road.

They were threatened with a knife and attacked resulting in one being knocked unconscious.

He had his wallet and mobile phone stolen. Both suffered bruising and swelling injuries.

Detectives are appealing for information following the incident on Wednesday (November 14 2018) at about 12.30am.

Anyone with information should call Detective Constable Chris Edwards at Norwich CID on 101 or call Crimestoppers anonymously on 0800 555 111.