Israel killed 22 people - including nine children - in strikes on Gaza City today, Palestinian officials say.
Gaza civil defence spokesman Mahmoud Bassal described the killings as a "horrific massacre".
Video purportedly from the scene of the attack on the Souq Firas area of the city showed the bodies of children being pulled from the rubble.
A total of 51 people have been killed across Gaza today, according to hospital medics in the Hamas-run territory.
Meanwhile, the Palestinian Red Crescent Society, said the oxygen station at Al-Quds Hospital in Gaza had stopped operating "due to Israeli occupation forces firing at it".
"Operations are currently being conducted using pre-filled oxygen cylinders, which are sufficient for only three days," the group said.
"Occupation forces are curr