The cause of the deadly stampede may have been the dispersal of a stinging substance, according to authorities.

Six people have died, most of them teenagers, in a stampede at a nightclub near Ancona in central Italy.

Firefighters said the incident happened after panic erupted in the wee hours on Saturday.

About 1,000 people were present at the Blue Lantern club in the town of Corinaldo on the Adriatic coast for a performance by Italian rapper Sfera Ebbasta, according to local reports.

The cause of the stampede was not immediately clear but first reports on Italian media said the teenagers were trying to escape from the nightclub after someone had set off a can of pepper spray.

“The cause may have been the dispersal of a stinging substance, the young people fled and trampled over each other. Sadly, six people died and dozens are injured,” the fire service said in a statement on Twitter.

About 120 people were injured, at least 10 of them seriously, local media reported, citing rescue authorities. Many of the injured suffered severe bruising while others had broken bones.

“We were dancing and waiting for the concert to start when we smelt this pungent odour,” a 16-year-old boy who was taken to the hospital told the media.

“We ran to one of the emergency exits but we found it blocked, the bouncers told us to go back.”