The incident took place near the eastern coastal city of Ancona.
Some reports say there was panic after pepper spray was fired inside the club in the town of Corinaldo but this has not been officially confirmed.
The Lanterna Azzurra club was packed at the time and many of the injured suffered crushing injuries.
The club was hosting a concert by Sfera Ebbasta, one of the best known Italian rappers, and up to 1,000 people were thought to be inside.
It’s enough to give a monument an identity crisis.
The Leaning Tower of Pisa is known worldwide for its precarious tilt – but now experts have revealed it’s going straight.
The tower’s Surveillance Group, which monitors restoration work, said the landmark is “stable and very slowly reducing its lean.”
The 57m (186ft) medieval monument has been straightened by 4cm (1.5in) over the past two decades, the team said.
“It’s as if it’s had two centuries taken off its age,” Professor Salvatore Settis explained.
When the tiny Italian town of Acquetico set up a trial speed camera, it did not expect to see a probable record: 58,568 speeding offences in just two weeks.
Local mayor Alessandro Alessandri set up the pilot after dozens of the 120 residents complained about speeding.
But even he could hardly believe the results that arrived on his desk.
The data showed, on average, a speeding car passed every few minutes in the 50km/h (31mph) zone – with the worst offender reaching 135km/h (84mph).
“It’s really madness, considering that we have inhabitants who regularly move within the village and cross the road,” Mayor Alessandri told Italy’s Ansa news agency.
Italy has been battered by fierce winds and rain which have left 11 people dead in the west and north, while schools and tourist sites closed in several regions amid fears for people’s safety.
Winds of up to 180km/h (110 mph) were reported, and two tornadoes ripped through the centre of the coastal town of Terracina, killing one person and leaving 10 others injured.
In the canal city of Venice, rising floodwaters overwhelmed many of its famed squares and walkways, with officials saying as much as 75% of the city is now submerged.
The search continues for missing people following flash flooding in parts of Spain, Italy and France.
Twelve died – including a British couple – when torrential rain lashed eastern Majorca in Spain. A five-year-old local boy is still missing.
A German couple is feared to be among the 12. Not all have been identified.
A flash flood on France’s south coast killed two people in Sainte-Maxime while a woman was found dead after a storm in Sardinia, Italy.
The actor was taken to a hospital in Olbia and released shortly afterward, officials said. His injuries were not believed to be serious.
A photo from Italy’s La Nuova showed the motorbike parked in front of the car Clooney appeared to have it. The car was seen with a smashed windshield.
President Donald Trump said the United States will not sign a joint agreement with other G-7 countries, an abrupt reversal that will further erode relations with key U.S. allies and underscore the country’s increasing isolation under Trump.
Trump announced his decision in a tweet while lashing out at Canadian Prime Minister Justin Trudeau, who expressed opposition to Trump’s trade policies at the conclusion of the contentious summit.