Copenhagen Police have arrested a 16-year-old boy in connection with Saturday afternoon’s attack on three men and one woman in Nørrebro’s Folkets Park.

The 16-year-old appeared before a magistrate in city court and is now being detained in a secure location. He was not jailed due to his age.

One of the victims was stabbed three times and suffered a collapsed lung during the attack. The four victims were driving near Folkets Park when they were assaulted by a group of between 10 and 12 people.

The area around the park is known for its open-air drug trade and has a history of gangs and violence. The most notorious example is the stabbing murder of an Italian tourist in 2003. In mid-April of this year, shots were fired at a car as it drove down Stengade. The shots apparently came from inside Folkets Park. In a separate April incident, three Polish victims were assaulted with guns and knives on Kapelvej.

“This cannot continue,” Lau Thygesen of the Copenhagen Police told bt.dk. “There cannot be areas of Copenhagen that are unsafe for people to enter.”

Police say that the 16-year-old in custody is known in the area and that they are continuing to look for other suspects. The search is being hampered because the victims were so shaken by the attack. Even though the assault occurred in broad daylight, neighbours said they could not identify the perpetrators.