The United Nations said the fighting would worsen an extreme humanitarian emergency, Reuters reports.

“Hell on Earth has returned to Gaza,” said Jens Laerke, spokespersonfor the UN humanitarian office in Geneva.

“Today, in a matter of hours, scores were reportedly killed and injured. Families were told to evacuate, again. Hopes were dashed,” said UN aid chief Martin Griffiths, adding that children, women and men of Gaza had “nowhere safe to go and very little to survive on”.

Israel has accused Hamas of refusing to release all the women it held. A Palestinian official said the breakdown occurred over female Israeli soldiers.