Five people were wounded, one of them seriously, during the night when a hand grenade was lobbed at the Cafe Nemoland in the Christiania district of Copenhagen.

A 22-year-old man suffered serious facial injuries, while four others suffered shrapnel wounds to the back and lower extremities. The 22-year-old was operated on during the night and is said to be in a stable condition.

Police have no clues as to who was responsible for the attack or, as yet, an indication of a motive. Eyewitnesses to the explosion had disappeared from the area by the time police officers arrived at the scene.

The police spokesman says the attack appears to have been random and that none of the five injured have been known to the police previously.

Thursday night’s apparently indiscriminate attack comes in the wake of a shooting in the Nørrebro district of Copenhagen on Wednesday in which a 29-year-old teacher was shot and seriously injured in front of his home.