An Israeli airstrike on a single residential block killed nearly 100 people on Tuesday, Gaza's civil defense agency said, leaving rescuers scrambling for survivors as Israel pursued its offensives in Gaza and Lebanon.

Israel's key ally and backer, the United States, called the strike — which killed a large number of children — "horrifying."

The bombing came with Israel facing an international backlash after its parliament overwhelmingly voted to ban UNRWA, the main United Nations aid agency working with Palestinians in Gaza and the occupied West Bank.