Police kept up their patrols on the streets of Clifton over the weekend in the hunt to catch a serial sex attacker.

There was an increased presence of officers in the area after dark.

The attacker – dubbed the Bristol Groper – has sexually assaulted five women in as many weeks.

His most recent attack happened in the early hours of Friday morning, when he pounced on his latest victim in Cotham, at the corner of Hampton Park and Cotham Hill, just off Whiteladies Road.

The attack happened five weeks after the first indecent assault on October 12.

Police revealed on Thursday that the others took place in Whiteladies Road, Alma Road, Pembroke Road and Hanbury Road, and stressed that none of the women were raped.

On Friday, Superintendent Ian Wylie, head of operations for Bristol, said: "This sort of offence is very rare but we would like women to take extra care – walk home with someone else, use a taxi and use well-lit streets.

"Women do need to be cautious but we don't want to raise concerns unnecessarily."

Until Thursday, police had not warned the public that there had been a string of sex attacks.

Ruth Jackson, vice president of the University of Bristol students union and responsible for student welfare issues, has spoken out about the issue and said it was worrying that the police had not warned women about the attacker earlier.

Supt Wylie said there was now a large team of officers involved in the investigation and there would be a big uniformed police presence in the Clifton area over the next few days to provide reassurance, give advice to women and find more witnesses.

He also appealed for any women who might have been attacked and not reported the matter to the police to come forward.

Supt Wylie would not go into details of how the attacker approached his victims but said there was a clear modus operandi.

He also said he was confident that with an experienced team of officers, the man would be caught.

The attacks have happened during the hours of darkness in the evening or into the early hours, with the victims women aged between about 20 and 30. The man the police are hunting is white, about 5ft 10ins tall, with dark hair. He is also said to have been wearing dark clothing.

Although there have been several weeks between the first attack and the latest assault, it is understood that detectives have only recently been linking the attacks.