Live updates: Follow the latest news on Israel-Gaza
At least 195 Palestinians died in Israel's attacks on Gaza's Jabalia refugee camp, the enclave's Hamas-run government said.
Israel said strikes on the camp, Gaza's biggest, on Tuesday and Wednesday killed two Hamas military leaders.
Hamas said on Thursday that 120 were still missing under the rubble after the bombardment while at least 777 were wounded.
Israel said the group had command centres and other “terror infrastructure under, around and within civilian buildings, intentionally endangering Gazan civilians”.
Palestinians sifted through rubble on Wednesday in a desperate hunt for trapped victims.
“It is a massacre,” said one witness.
The strikes on the camp could be war crimes, UN human rights officials said.
“Given the high number of civilian casualties and the scale of destruction following Israeli air strikes on Jabalia refugee camp, we have serious concerns that these are disproportionate attacks that could amount to war crimes,” the UN High Commissioner for Human Rights wrote on social media site X, formerly Twitter.
The Gaza Health Ministry said at least 8,796 Palestinians in the narrow coastal enclave, including 3,648 children, had been killed by Israeli strikes since October 7.
The Al Shati camp, another of Gaza's biggest refugee sites, was also shelled overnight, witnesses told The National.
Clashes between Hamas and the Israeli army have intensified in Gaza, particularly in the Al Karama area.
Several people were injured when a house next to a bakery on Nasser Street in western Gaza city was targeted while people queued up for bread, a witness told The National.
Explosions were heard in the early hours of Thursday around Al Quds Hospital, the Palestinian Red Crescent said.
An area near Al Shifa Hospital was also hit, a witness said.
Israeli authorities had previously warned the hospital to evacuate immediately, which UN officials said was impossible without endangering patients.
The Israeli military said one soldier was killed in Gaza on Wednesday. Fifteen were killed on Tuesday.
More foreigners to leave Gaza
More foreigners prepared to leave the besieged enclave on Thursday.
At least 320 foreign citizens on an initial list of 500, as well as dozens of severely wounded Gazans, crossed into Egypt on Wednesday under a deal among Israel, Egypt and Hamas.
Passport-holders from Australia, Austria, Bulgaria, the Czech Republic, Finland, Indonesia, Italy, Japan, Jordan, the UK and the US were among those evacuated.
Gaza border officials said the border crossing would reopen on Thursday so more foreigners could leave. A diplomatic source said about 7,500 foreign passport holders would leave Gaza over the next two weeks.
Pressing an offensive against Hamas militants, Israel has bombed Gaza by land, sea and air in its campaign to wipe out Hamas after the militant group's cross-border rampage into southern Israel on October 7.
Israel said Hamas killed about 1,400 people, mostly civilians, and took about 240 hostages.