A teenage girl was forced to undress in the street on Monday by a cyclist who claimed to be armed with a gun.

The attack, which lasted for almost half an hour, took place in Comberton, Cambridge, while it was still daylight.

The 18-year-old was walking her dog at 5.30pm when a youth approached from behind on his bicycle.

Speaking to the Cambridge News, the victim said: “He told me to start taking my clothes off or he would shoot me. He kept reaching for a weapon in his pocket. I don’t know what it was but I didn’t see a gun.

“I had to take some of my clothes off and then he told me to take my knickers off because he wanted to take them with him.”

The attacker fled after the teenager burst into tears. He has been described as white, 5ft 6in to 5ft 7in, 17 to 20 years old and clean shaven.

The victim added to the description that he “had a spotty face that looked sore and blond spiky hair and was wearing a tracksuit."

Detective Sergeant Andy Crocker, leading the investigation, urged anyone with any information to come forward, and said that this is being treated as an isolated incident.

However, it does come in the wake of a string of attacks in the city centre, some involving students from the University of Cambridge.

The number of police patrols was increased in the centre after the most recent attack at the beginning of February in the hope of preventing further incidents.