Residents of the German city of Wuppertal have expressed concern after a group of young radical Islamists started taking to the streets late at night, trying to deter revellers from drinking and gambling.

The self-styled “Sharia Police” have been patrolling an area around the city’s main train station, declaring the popular nightlife area to be a “Sharia Controlled Zone”. Deutshe Welle reports that witnesses have seen them handing out leaflets urging people not to drink alcohol, attend concerts, gamble, watch pornography or visit prostitutes.

The men are believed to be from the Salafi sect of Islam, which is closely related to the puritanical Wahhabi belief practised in Saudi Arabia. They walk around dressed in orange high-visibility vests with the words “Sharia Police” written on the back in English.

The city’s real police said they stopped 11 men aged between 19 and 33 on Wednesday night, and may bring charges of illegal assembly against them. However, after numerous residents complained to them, they have now also set up a hotline allowing people to report their concerns about the group.

Local police chief Birgitta Rademacher said that provocation and intimidation “won’t be tolerated”, adding that only officers appointed by the state had the right to act as police in Germany.

The city’s mayor, Peter Jung, supported the police’s stance: “These people’s intention is to provoke and intimidate and force their ideology [upon others],” he said.

“This is an open and tolerant city, which is proud of the fact that people of different religions and convictions live together in peace.”

The group had originally posted a video to Youtube, proudly boasting of their activities. Their account has now been suspended, however, although others have reproduced it: