The Palestinian territory's Hamas-run health ministry blamed an Israeli strike and said five critically injured foreign workers had arrived in hospital. Israel's military denied striking the UN compound in Deir al-Balah.

It comes after Israel said it was resuming fighting in Gaza following a two-month ceasefire - launching a wave of strikes that killed more than 400 people, according to Gaza's health ministry. On Tuesday, Israel's Prime Minister Benjamin Netanyahu said it had ‘resumed combat in full force’.

The UN initially said two of its workers had been killed but later clarified that the second person was not a staff member. The UN Office for Project Services (UNOPS) said an ‘explosive ordnance was dropped or fired’ at the building, which was in an "isolated" location. It added there was no confirmation on the nature of the incident or the type of artillery used.

UNOPS executive director Jorge Moreira da Silva described the incident as ‘not an accident’ and added that ‘UN personnel and its premises must be protected by all sides’. Footage verified by the BBC showed injured people - two still wearing blue UN flak jackets - arriving at a hospital in an ambulance and a UN car. Separately, at least 20 people were killed in air strikes across Gaza overnight, after Israel said it was resuming fighting in the Palestinian territory.

Two civilians were killed and five others injured when an Israeli drone hit a tent near the al-Mawasi humanitarian zone, the Palestinian Wafa news agency reports, citing Red Crescent medics. Israel's army said it had targeted what it called a Hamas military site, from where the group was preparing to fire into Israel. Vessels controlled by Hamas were also hit, the army said. Wafa says a woman and child were killed in an air strike north of Khan Younis overnight into Wednesday, while four others were killed in a strike in Gaza City. Gaza's health ministry said that 436 people had been killed in strikes since Tuesday, including 183 children. (BBC)