Six people, including five teenagers, were crushed to death in the early hours of Saturday in a stampede at a packed nightclub, officials said.
Fire brigades said the stampede took place in the Lanterna Azzurra nightclub in the town of Corinaldo, near Ancona, on the Adriatic coast, where rapper Sfera Ebbasta was performing.
Three girls, two boys and a mother who had accompanied her child to the event, died in the incident. More than 100 other people were injured, including a dozen who were seriously hurt.
The local fire brigade said someone might have sprayed a substance like pepper spray into the crowd, triggering a panicked rush to the emergency exits.
La Repubblica newspaper quoted a survivor as saying that at least one of the exits was blocked. Another eyewitness said a wall inside the club had collapsed in the melee.
The names and ages of the victims were not immediately given.