An explosion that shook a refugee camp in southern Lebanon was caused by an electrical short circuit in a storage area for oxygen bottles used to treat coronavirus patients, the Palestinian Hamas group said on Saturday.

However, a Lebanese security official disputed the claim and said that the explosion was clearly caused by ammunition. The official did not elaborate.

Lebanon’s state-run National News Agency reported late on Friday that arms stored on behalf of Hamas had exploded in Burj Shamali camp, killing and wounding a number of people.

A security official also said the explosion resulted in casualties but did not give a breakdown.

On Saturday, Hamas described the explosion as an “incident” and said that a fire in the refugee camp in the southern port city of Tyre caused limited damage.

In a later statement, the group said that one of its members, Hamza Chahine, was killed and called on its supporters to take part in his funeral on Sunday afternoon at a mosque in the camp.

Hamas said the oxygen bottles and containers of detergents stored at the camp were to be distributed as part of its aid work in the camp.

“Hamas condemns the misleading media campaign and the spread of false news that accompanied the incident,” the militant group said. It described reports about the cause of the blast and the “deaths of dozens” as baseless.

Immediately after the explosion, Lebanese troops were stationed around the camp and briefly prevented people from entering or leaving.

The NNA said the state prosecutor in southern Lebanon has asked security agencies and arms experts to inspect the Hamas arms storage site inside the camp.

Lebanon is home to tens of thousands of Palestinian refugees and their descendants. Many live in 12 refugee camps are scattered around the small Mediterranean country.