Rescuers were searching rubble through the night to find more victims of the blast that also injured dozens.
What caused the explosion?
A natural gas leak was the apparent cause of the incident at Havana’s 96-room Hotel Saratoga.
Speaking from the scene on Cuban television, the country’s president Miguel Diaz-Canel told reporters it was not a bomb or an attack, but said "it’s just a very unfortunate accident".
Mr Diaz-Canel said 50 adults and 14 children were hospitalised after the blast, and that families in buildings near the hotel affected by the explosion had been transferred to safer locations.
The 19th-century structure in the city’s Old Havana neighbourhood did not have any guests at the time because it was undergoing renovations ahead of a planned reopening on Tuesday.
Relatives of missing people remained at the site of the explosion late on Friday night (6 May) as rescuers continued to search through rubble, while others gathered at hospitals where the injured were being treated.
No tourists were reported injured in the explosion, but state TV said the government has not yet made public the nationalities of the victims.