Police are hunting a bike-riding serial sex attacker who targets Cambridge University students.
Cambridgeshire Police have launched Operation Majesty to catch the offender who is believed to have first struck in August last year. He is so far known to have attacked nine women. Eight of his victims studied at the university.
On each occasion the attacker, who uses a bicycle to prowl city streets, has grabbed and groped his female victims but fled when they began struggling or screaming. The victims range in age from 19 to 32.
Dr Mark Wormald, a senior tutor at Pembroke College, has sent an email to students, fellows and staff, urging vigilance.
His comments follow the latest attack on Saturday, which did not involve a student from the college but which police are linking to previous assaults.
Detective Sergeant Phil Priestley said: "This latest incident is extremely similar to the other attacks in this series and we have reasonable grounds to believe that they have all been committed by the same man.
"It is reasonable to suspect that someone out there knows who he is and I would urge them to do the right thing and get in touch. This person may have boasted to friends, or made mention of his unusual activities.
"He appears to have good local knowledge and is travelling to and from the offence locations on a bike. It is likely other people may have seen him during the morning of this latest incident.
"We have increased patrols in the areas where offences have been committed and would urge women to take the usual sensible precautions of not walking at night and early in the morning alone."
Police have issued an e-fit image of the attacker who is described as white, aged 20 to 30, of medium build and physically strong. He is between 5ft 10in and 6ft.
In his email, quoted in the Cambridge News, Dr Pembroke said: "The predator continues to operate in the vicinity of the college and its hostels in the west and south of the city.
"You are requested to remain extremely vigilant when walking in and around the city, particularly after nightfall.
"Students who are travelling across Cambridge after dark on foot rather than on bicycles are urged to walk in pairs wherever possible and to carry a mobile phone and if possible a personal alarm."
Crimestoppers has offered a reward of up to £5,000 for information leading to the arrest of the person responsible.
Ann Scott, eastern regional manager at Crimestoppers, said: "These incidents are unsettling for the whole community and it is vital this offender is caught and brought to justice."