Rotterdam police have issued a short video of a man they want to interview in connection with a string of sex attacks across the city.

The police say they have had six reports of attacks since mid-November, all of which took place in the centre and northern part of the city, late at night and early in the morning.

Three of the victims have made a formal report about the attacks and the police say there are strong indications all three are connected.

The man, aged 25 to 50, has dark hair and a beard and appears to move around by bike. He speaks Dutch, police said.

The police have also called on other victims to come forward. “We understand that sexual assault has a major impact but we would urge victims to report to us,” the police said. “Every piece of information can help.”

Last week, the Rotterdam force issued an appeal to women to be extra alert while out at night.