A fire and explosion in a Bucharest nightclub killed 27 people and injured 155 during a rock concert that featured fireworks late on Friday, Romanian government officials and witnesses said.
In one of the capital's worst disasters in decades, about 400 people, mostly young adults, stampeded for the exit as the club in the basement of a Communist-era factory filled with smoke.
Several witnesses said there were fireworks inside the club. Colectiv Club's Facebook page said the show would feature pyrotechnic effects.
A pillar and the club's ceiling went up in flames and then there was an explosion and heavy smoke, the witnesses said.
TV footage showed police officers and paramedics trying to resuscitate young people lying on the pavement while sirens wailed with more ambulances deployed to the scene.
"There was a stampede of people running out of the (Colectiv) club," a man who escaped without shoes told Reuters.
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A young woman who was released from the hospital after minor injuries described the club bursting into flames.
"In five seconds the whole ceiling was all on fire. In the next three, we rushed to a single door," she told television station Antena 3.
The victims were admitted to 10 hospitals in Bucharest, said Deputy Interior Minister Raed Arafat.
"The situation is slowly stabilising ... we have many people with burns, intoxicated with smoke and people squashed," he said, adding many victims have no identification.
Deputy Prime Minister Gabriel Oprea said an investigation into the causes of the incident was already under way, and the health minister launched a public appeal for blood donations.
Romania's President Klaus Iohannis said in a statement: "I want to assure you of all support from rescuing forces and ask you to trust they put all efforts to limit the impact of this catastrophe."
An emergency meeting of cabinet ministers was set for early on Saturday to assess the incident.
Some of the deadliest nightclub disasters in the world were started by fireworks.
In the southern Brazilian college town of Santa Maria in 2013, a musician lit an outdoor flare inside the Kiss nightclub and started a fire that killed at least 241 people, investigators said. It was Brazil's worst fire at an entertainment venue since a disgruntled employee set fire to a circus in 1961, killing well over 300 people.
In China, 309 people died in a discotheque blaze in 2000 and fireworks were also blamed for nightclub fires in Russia's Perm that killed 156 people in 2009 and in Argentina's Buenos Aires in 2004 that killed 194.