Night club fire scene, Kocani, North Macedonia, March 16, 2025. (REUTERS/Ognen Teofilovski)

The fire was caused by "pyrotechnic devices" used during a concert, Toskovski said.

A video from the event, verified by Reuters, shows a band playing on stage flanked by two flares firing white sparks into the air. The sparks set the ceiling alight above the band, who appear to step away as the video cuts.

Firefighters doused the charred and smoking entrance to the club, named 'Pulse,' TV footage from a local broadcaster showed.