Havana: A powerful explosion apparently caused by a natural gas leak has killed eighteen people and injured at least 40 when it blew away outer walls from a five-star hotel in the heart of Cuba’s capital.

The death toll in an explosion that hit a well-known hotel in downtown Havana on Friday rose to 18 from an initial assessment of eight, according to a statement from Cuba’s presidency posted on Twitter.

A pregnant woman and a child were among those killed, it added.

No tourists were staying at the 96-room Hotel Saratoga because it was undergoing renovations, Havana Governor Reinaldo García Zapata told the Communist Party newspaper Granma.

“It has not been a bomb or an attack. It is a tragic accident,” President Miguel Díaz-Canel, who visited the site, said in a tweet.

The blast on Saturday (AEST) happened as Cuba is struggling to revive its key tourism sector that was devastated by the coronavirus pandemic and is being negatively impacted by the war in Ukraine.

Earlier, Cuba’s national health minister, José Ángel Portal, said that hospitals had received about 40 injured people, but estimated that the number could rise as the search continues for people who may be trapped between the debris of the 19th century structure in the Old Havana neighbourhood of the city.

Granma reported that local officials said 13 people were missing. An elementary school next to the hotel was evacuated and local news media said no children were hurt.