At least 21 people including several children have died after a bus crashed off a flyover near Venice and burst into flames, officials say.
The bus broke through a barrier and plunged almost 15m (50ft) near railway tracks in the district of Mestre, which is connected to Venice by a bridge.
Five Ukrainians, one German and the Italian driver were among the dead, city prefect Michele Di Bari said.
Venice Mayor Luigi Brugnaro said a “huge tragedy” had taken place.
“An apocalyptic scene, there are no words,” he said on social media.
One rescuer spoke of a “tragedy of young people, if not very young people, except for a few adults”.
Three children including a baby were among the dead, emergency services said. Interior Minister Matteo Piantedosi said that the toll could rise.
Fifteen people are known to have been injured, five of them seriously. Venice officials said they included Ukrainians, Austrians, Spaniards and other foreign tourists.
Among the injured were two 16-year-olds and two younger children, the local governor said.
The bus, carrying 39 people, crashed at around 19:45 (17:45 GMT) on Tuesday. It had apparently been rented by a local company to pick up tourists from the historic centre of Venice to a campsite in the nearby Marghera district.
The vehicle is thought to have been a hybrid, powered by electric batteries and methane gas. Italian reports suggest the gas tank exploded on impact and fire brigade commander Mauro Longo told Il Gazzettino website that the batteries caught fire and made the task of clearing the bus a complex operation.
Witnesses told Rai TV they could hear people screaming but the flames were too high to intervene.
A 27-year-old Gambian worker and a colleague were among the first people to reach the scene. He told how he had pulled three or four people from the bus, including a young girl.
What is unclear is why the bus left the flyover on a downhill stretch of the road and careered through a guard rail and metal barrier. Police are looking at video from security cameras near the crash site.
The 40-year-old driver had worked for the bus company for seven years and there was no indication on the road that he had tried to brake before the crash.
One theory is that he may have become ill in the moments before the accident, reports said.
Firefighters eventually removed the wrecked bus from the scene early on Wednesday.
A reception point staffed by psychologists and psychiatrists has been set up at a nearby hospital to provide support for the victims’ families.
Italy’s Prime Minister Giorgia Meloni said her thoughts were with the victims and their family and friends,” she said.
In 2013, 38 people were killed after a coach lost control on a viaduct near the south Italian town of Monteforte Irpino, hitting several other cars before falling into a ravine.