Rescuers in Cuba's capital searched through the night for survivors of an explosion that killed at least 22 people and injured dozens at a luxury hotel that once hosted Jay-Z and Beyonc.

A natural gas leak is believed to be the cause of Friday's blast at Havana's Hotel Saratoga. The 19th-century structure in the city's Old Havana neighborhood did not have any guests at the time because it was undergoing renovations.

Rescuers using search dogs clambered over huge chunks of concrete looking for more survivors after one was found in the shattered ruins of the hotel. The relatives of missing people were at the site overnight. The injured were being treated at the hospitals.

The hotel's outer walls were blown away by the explosion, leaving the interiors of many rooms exposed.

Avellar was waiting for news of Odalys Barrera, a cashier who has worked at the hotel for five years. She considers her a sister and is the godmother of the girls.

The explosion is a blow to the country's vital tourism industry.

Cuba was struggling with tightened sanctions even before the coronaviruses kept tourists away. Cubans in the U.S. were not allowed to send money to their families in Cuba.

The war in Ukraine deflated a boom of Russian visitors, who accounted for almost a third of the tourists arriving in Cuba last year.

The lower floors of the hotel appeared to have suffered the most damage from the blast. It was possible to distinguish mattresses, pieces of furniture, hanging glass, tattered curtains and cushions covered in dust because of the missing walls.

The chief of hospital services at the Ministry of Health said at least 74 people had been injured. The office of the president said that there were 14 children.

The number of injured could rise as the search continues, according to Cuba's national health minister. Rescue workers are still looking for a large group of people who may be under the rubble.

The shattered hotel remained closed as workers under the glow of emergency lights lifted huge pieces of wall and masonry from the site.

Rescuers refused to answer questions because they were told not to.

The school is next to the hotel. Five of the students suffered minor injuries.

The Capitol building in Cuba had broken glass and damaged masonry after the explosion.

The hotel is owned by the Cuban military and was renovated in 2005 as part of the revival of Old Havana. The company said it was investigating the cause of the blast and did not respond to an email from the AP asking for more information about the hotel renovation.

High-ranking U.S. government delegations have visited the Hotel Saratoga in the past. Jay-Z and Beyonc stayed there.

Two badly damaged apartment buildings are being evaluated next to the hotel. Families in affected buildings have been moved to safer locations.

The explosion threw me to the ground, and my head still hurts. Everything was very fast.

The relatives of people who worked at the hotel went to the hospital to look for their loved ones. Beatriz Céspedes Cobas was searching for her sister.

She had to work today. She said she works two blocks away. I didn't associate the explosion with the hotel until I felt the noise.

Mexican Foreign Relations Secretary Marcelo Ebrard said that the visit would still take place, despite the fact that Mexican President Andrn Lpez Obrador was scheduled to arrive in Havana late Saturday.