AT least 21 people have been killed after an Israeli air strike on an apartment building in northern Lebanon, according to the Red Cross.

There was no immediate comment from the Israeli military and it was not clear what the target was.

The strike hit a small apartment building in the village of Aito, far from the Hezbollah militant group’s main strongholds in the south and east of the country.

Earlier on Monday, an Israeli air strike on a hospital courtyard in the Gaza Strip burned at least four people alive and triggered a fire that swept through a tent camp for people displaced by the war, leaving more than two dozen with severe burns.

The Israeli military said the strike in Gaza targeted militants hiding out among civilians, without providing evidence.

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In recent months it has repeatedly struck crowded shelters and tent camps, alleging that Hamas fighters were using them as staging grounds for attacks.

Al-Aqsa Martyrs Hospital in the central city of Deir al-Balah was already struggling to treat a large number of wounded from an earlier strike on a school-turned-shelter that killed at least 20 people when the early morning air strike took place, with fire engulfing many of the tents.

Several secondary explosions could be heard after the initial strike, but it was not immediately clear if they were caused by weapons or fuel tanks.

Footage showed children among the wounded. A man sobbed as he carried a toddler in his arms with a bandaged head. Another small child with a bandaged leg was given a blood transfusion on the floor of the packed hospital.

Hospital records showed that four people were killed and 40 injured.

Twenty-five people were transferred to Nasser Hospital in southern Gaza after suffering severe burns, according to Al-Aqsa Martyrs Hospital.