Police are continuing to investigate an incident where a teen had a knife held to her throat and her boyfriend slashed in a terrifying attack.

The 17-year-old City College Norwich student, who does not want to be named, had been cycling with her 20-year-old boyfriend on Mile Cross Road, Norwich, when they were subjected to a torrent of verbal abuse from a group of young people.

The victim said they had called her fat before one of the group started attacking her boyfriend.

The teen said her boyfriend was cut in the arm after he pulled the attacker off her.

The offender slashed the female victim's bike tyres before running off down Hansard Close where he was challenged by members of the public but managed to get away.

A police spokesman said the investigation into the incident, which happened at about 4.50pm on February 28 this year, was "ongoing".

Call police on 101.