A foreign national was killed and four others were wounded in an Israeli airstrike on the site of a United Nations headquarters in central Gaza City on Wednesday, Gaza's health ministry said.

The death toll rose to more than 400, Gazan authorities said, marking one of the deadliest days since the war began. The attacks came after a breakdown in talks to release hostages.

Prime Minister Benjamin Netanyahu’s office said he had ordered the aerial attacks after Hamas’s “repeated refusal” to release the remaining hostages it holds. “This is just the beginning,” he said.