At least 21 people have been killed and dozens more are believed to be trapped under rubble after a bombed-out six-storey building housing displaced Palestinians collapsed in Gaza City on Wednesday.

The apartment block was damaged by Israeli bombing and had been leaning precariously to one side for some time. Despite its dangerous condition, the building was housing around 100 displaced Palestinians, including 50 children, according to the UN.

The building collapsed in the early hours of Wednesday morning, crushing nearby tents which were also being used to house homeless Palestinians. 

Five children were among the 21 bodies recovered, civil defense workers said. Some 25 injured people have already been pulled from the rubble, and rescuers told the BBC that the voices of trapped victims could be heard beneath the debris.

Between 70 and 100 people are believed to be trapped under the destroyed building, Alessandro Mrakic, head of the United Nations Development Programme’s (UNDP) Gaza office told reporters. With Israel preventing machinery, fuel, and rescue equipment from entering Gaza, “there are actually people digging with their bare hands,” Mrakic said. 

According to UN figures, roughly 82% of Gaza’s buildings have been damaged, with two thirds of them destroyed, since Israel began bombing the strip after Hamas’ surprise attack in October 2023. There are currently around 400 buildings at imminent risk of collapse across the territory, Mrakic warned on Wednesday.

Although a de jure ceasefire has been in place since last October, Gaza’s Hamas government has accused Israel of violating the truce more than 4,000 times since then. Israel has either denied these incidents, or characterized them as legitimate responses to breaches by Hamas or threats to its troops.

More than 73,000 Palestinians, the vast majority of them civilians, have been killed in Gaza since October 2003, according to the Gaza Ministry of Health. 1,369 of those have been killed since the ceasefire came into effect. At least two additional people were killed on Wednesday when Israeli forces struck a house in Gaza City and a refugee camp in the center of the strip, the ministry said.