German police have put out an appeal for information about a gang of rapists operating in central Dusseldorf.

Four suspects aged between 24 and 29 were arrested earlier this year. Three of them are still in custody and facing multiple sexual assault charges, officers said in a statement.

Read more: German group rape suspect turns himself in, three more in custody

The group is accused of targeting women outside nightclubs in Dusseldorf's old town in 2018, and introducing themselves as Jamal, Sammy, Momo, Memo or Bilal. 

They allegedly lured the women either to an apartment in Krefeld, or to a hotel room booked in the victim's name, where the sexual assaults took place. The victims were held for several hours, and in some cases the perpetrators filmed the attacks on their cell phones, police said.

Investigators said it was likely there were further victims who had not yet contacted police. They appealed for witnesses or anyone with information to come forward. 

DW sends a daily selection of hard news and quality journalism. Sign up here.