A deadly explosion hit a well-known hotel in downtown Havana, tearing a gash several floors high in the side of the building, killing at least 18 people and sending 74 more to hospital, witnesses and state media have said.
Speaking from the scene on Cuban television, President Miguel Diaz-Canel said the blast at the historic Hotel Saratoga appeared to have been caused by a gas leak.
"In no case was it a bomb or an attack," he later told Reuters as he left the capital's Calixto Garcia hospital, where many of the injured were treated. 'It's just a very unfortunate accident."
Survivors recounted hearing a "terrible explosion" at the scene.
The first four floors of the establishment, which was empty of guests while being renovated, were gutted in the late-morning blast that sent a cloud of dust and smoke billowing into the air.
"Search and rescue work continues in the hotel, where it is possible that other people are trapped," Havana Communist Party official Luis Antonio Torres Iribar said, with several people reported missing.
The blast tore off large parts of the facade, blew out windows and destroyed cars parked outside the hotel, which is known for having hosted celebrities such as Madonna, Beyonce, Mick Jagger and Rihanna.
The dome of a nearby Baptist church collapsed.
Inside the hotel at the time were employees preparing for its post-refurbishment reopening, scheduled for next Tuesday.
According to Miguel Garcia, director of the Calixto Garcia hospital treating some of the wounded, 11 were "in an extremely serious condition."
Miguel Hernan Estevez, director of the hospital Hermanos Almejeiras, said a two-year-old boy had undergone surgery for a fractured skull.
"So far we have no information that any foreigner was either injured or killed, but... this is preliminary information," added Tourism Minister Juan Carlos Garcia Granda.
Roberto Calzadilla of state company Gaviota, which owns the hotel, said the explosion happened while a gas tank was being refilled.
"It was neither a bomb nor an attack, it was an unfortunate accident," said President Miguel Diaz-Canel, who arrived at the scene an hour after the blast accompanied by the prime minister and National Assembly president.
Cuba was hit by a wave of anti-communist bombing attacks on hotels in 1997, in which an Italian tourist was killed and six people injured.
Ambulances and fire trucks rushed to the scene and police cordoned off the area, dispersing people who swarmed to the hotel near Havana's emblematic National Capitol Building that housed Congress prior to the Cuban revolution.
It is also next to a school, but no pupils were injured, according to the presidency.
According to the website of the Saratoga Hotel, it is an upmarket establishment with 96 rooms, two bars, two restaurants, a spa and gym.
It was built in 1880 to house shops and converted into a hotel in 1933.
Mexico's Foreign Minister Marcelo Ebrard, meanwhile, said President Andres Manuel Lopez Obrador would not cancel a trip to Cuba planned for Sunday.
"Our solidarity to the victims and affected, as well as to the people of that dear brotherly people," the minister tweeted.
Bolivian leader Luis Arce also expressed solidarity with the Cuban people on Twitter, offering "all our support" to victims' families.
