HAVANA (AP) — A powerful explosion apparently caused by a natural gas leak killed at least 22 people, including a child, and injured dozens on Friday when it blew through the exterior walls of a luxury hotel in heart of the Cuban capital.

No tourists were staying at the Saratoga Hotel in Havana, which has 96 rooms, because it was being renovated, Havana Governor Reinaldo García Zapata told the Communist Party newspaper Granma.

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

Dr Julio Guerra Izquierdo, head of hospital services at the Ministry of Health, told reporters that at least 74 people had been injured. Among them were 14 children, according to a tweet from Díaz-Canel’s office.

Díaz-Canel said families in buildings near the hotel affected by the blast had been moved to safer locations.

Cuban public television reported that the explosion was caused by a truck that supplied natural gas to the hotel, but did not provide details on how the gas ignited. A white tanker truck was seen being pulled from the site as rescuers hosed it down with water.

Tourism Minister Juan Carlos García said the hotel was due to reopen on Tuesday.

The blast sent smoke into the air around the hotel with people on the street watching in awe, one saying “Oh my God”, and cars honking their horns as they sped away from the scene, showed a video. It came as Cuba struggles to revive its key tourism sector which has been devastated by the coronavirus pandemic.

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Cuban Health Minister José Ángel Portal told The Associated Press that the number of injured could rise as the search for people who may be trapped in the rubble of the 19th-century structure in the neighborhood of La Old Havana from the city continues.

“We are still looking for a large group of people who may be under the rubble,” said Lt. Col. Noel Silva of the fire department.

A school of 300 students next to the hotel was evacuated. García Zapata said five of the students suffered minor injuries.

Police cordoned off the area as firefighters and rescue workers worked inside the wreckage of the iconic hotel about 100 meters from Cuba’s Capitol.

The hotel was first renovated in 2005 as part of the Cuban government’s revival of Old Havana and is owned by the Cuban military’s tourist arm, Grupo de Turismo Gaviota SA. The company said it was investigating the cause of the explosion and did not immediately respond to an email asking for more details about the hotel and the ongoing renovation.

The Saratoga Hotel has been used frequently by VIPs and political figures, including high-ranking US government delegations. Beyoncé and Jay-Z stayed here during a visit to Cuba in 2013.

Photographer Michel Figueroa said he was passing the hotel when “the explosion knocked me to the ground and I still have a headache… Everything was very quick.

Worried relatives of people who worked at the hotel showed up at the hospital in the afternoon to pick them up. Among them was Beatriz Céspedes Cobas, who was looking for her sister in tears.

“She had to work today. She is a housekeeper,” she said. “I work two blocks away. I felt the noise, and at first I didn’t even associate the explosion with the hotel.

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Yazira de la Caridad said the blast shook her house a block from the hotel: “The whole building shook. I thought it was an earthquake.

In addition to the pandemic’s impact on Cuba’s tourism sector, the country was already grappling with sanctions imposed by former US President Donald Trump that were kept in place by the Biden administration. The sanctions have limited visits by American tourists to the islands and restricted remittances from Cubans in the United States to their families in Cuba.

Tourism had started to pick up a little early this year, but the war in Ukraine has served a boom in Russian visitors, who made up nearly a third of tourists who arrived in Cuba last year.

The blast came as the Cuban government held the final day of a tourism convention in the iconic beach town of Varadero aimed at attracting investors.

Mexican President Andrés Manuel López Obrador is due to arrive in Havana for a visit on Saturday evening and Mexican Foreign Secretary Marcelo Ebrard said the visit would still take place.

García Zapata said structures adjacent to the hotel are being assessed, including two badly damaged apartment buildings. The nearby Martí Theatre, the Yoruba Association and the Capitol had shattered glass and damaged masonry.

Mayiee Pérez said she rushed to the hotel after receiving a call from her husband, Daniel Serra, who works at a currency exchange inside the hotel.

She said he told her, “I’m fine, I’m fine. They took us out. But she couldn’t reach him after that.