Police in Copenhagen have set up four “no go” zones aimed at barring violent offenders from popular night-life areas in a bid to reduce violence in a country known for its low crime rates.

Under a new law, Danish courts can exclude people convicted of violent crime from “night life zones” set up by police, effectively controlling after-dark access to whole streets popular with partygoers.

“We have definitely got a new tool, a tool that affects the few, but which helps the many,” Copenhagen police inspector Tommy Laursen told Reuters.

In an early application of the new law, a court in Helsingor last week gave a 24-year-old Dane a five-month prison sentence for violent behaviour.

In addition, he was handed a nine-months ban from visiting pubs, restaurants and places that serve alcohol between midnight and 5 a.m. as weall as being excluded from night-life zones.

In Copenhagen, prosecutors will on Monday use the new law in a violent crime case against a 31-year-old man.

Despite having declined in recent years, violence in bars and clubs is a major contributor to Denmark’s violent crime statistics.

Many of those convicted of violence in night life venues are repeat offenders, Laursen said.

Violating a ban, which can last up to two years, will initially result in a fine of 10,000 Danish crowns ($1,500). A second offence means 30 days in prison, Laursen said.