The death toll from a powerful explosion at a luxury hotel in central Havana climbed to 22, with 64 people injured, said the Cuban Presidential Office in an update on Friday evening.
A previous report said at least 18 people were killed and over 50 others hospitalized.
Cuban President Miguel Diaz-Canel, who visited the site of the blast and a local hospital, said, "The explosion was not a bomb nor an attack, but a regrettable accident."
A gas leak is thought to be the cause of the massive explosion at Hotel Saratoga, according to the presidential office.
Seated opposite the island's National Capitol building, the five-star hotel was preparing to reopen on May 10 as part of the revival of tourism industry on the island.
At present, rescue operations are still underway as traffic has been diverted from the surroundings of the hotel.
"Patients are currently treated in eight health facilities in Havana, including two pediatric hospitals," said Julio Guerra, head of the Cuban Health Ministry's hospital services.
Havana Governor Reinaldo Garcia stressed the importance of solidarity of the population after the tragic event.
The blast also caused damage to buildings near the hotel, he said, adding that "thousands of people continue volunteering to donate blood."
An investigation into the explosion is underway, local media reported.