Palestinian health authorities said at least 146 people had been confirmed killed in the third day of Israel's latest bombing campaign, one of the deadliest waves of strikes since a ceasefire collapsed in March.
Many hundreds more wounded were being treated in hospital, and countless others were still buried under rubble.
Israel says it is mobilising to seize more ground in the Gaza Strip in a new campaign dubbed "Operation Gideon's Chariots," which follows a visit this week to the Middle East by US President Donald Trump.
It has halted all supplies entering the Gaza Strip since the start of March, leading to rising international concern over the plight of the enclave's 2.3 million residents.
Taher al-Nono, the media advisor for the Hamas leadership, told Reuters a new round of indirect talks with the Israeli delegation in Doha began on Saturday, discussing all issues "without pre-conditions".
"The Hamas delegation outlined the position of the group and the necessity to end the war, swap prisoners, the Israeli withdrawal from Gaza and allowing humanitarian aid and all the needs of the people of Gaza back into the strip," he added.
Israeli Defence Minister Israel Katz also said in a statement that negotiations on a deal to release Israeli hostages held by Hamas had resumed in Doha.
He noted that the talks had started without Israel first agreeing to a ceasefire or to lift its blockade.
Israel's military said it was conducting extensive strikes and mobilising troops with the aim of achieving "operational control" in parts of the strip.
Gaza health authorities said most of those killed on Saturday were in towns on the northern edge of the enclave including Beit Lahiya and the Jabalia refugee camp as well as in the southern city of Khan Younis.
They said 459 people had been injured.
Israeli forces had told people to leave the northern areas on Friday.
Talks since March have failed to restore a truce under which Hamas would release remaining hostages captured in the October 2023 assault on Israel that precipitated the war.
Hamas has long said it would not free them unless Israel ends its campaign; Israel says it will fight on until Hamas is dismantled.
United Nations experts say famine looms in the strip more than two months after Israel halted all deliveries of supplies.
United Nations aid chief Tom Fletcher asked the Security Council this week if it would act to "prevent genocide".
Israel blames Hamas for the suffering of civilians for operating among them and hijacking aid, which Hamas denies.
Israel says enough food reached the Gaza Strip during the six-week ceasefire at the start of the year to stave off hunger for now.
On Friday, Trump acknowledged the enclave's growing hunger crisis and the need for aid deliveries.
A US-backed foundation aims to start distributing aid to Gazans by the end of May using private US security and logistics firms.
The UN has said it will not work with the group because it is not impartial, neutral or independent.
Gaza's health system is barely operational with hospitals hit repeatedly by the Israeli military during the 19-month war and medical supplies drying up.
Israel's declared goal in the Gaza Strip is the elimination of the military and governmental capabilities of Hamas, which attacked Israeli communities on October 7, 2023, killing about 1200 people and seizing about 250 hostages.
Its military campaign has devastated the crowded enclave, pushing nearly all inhabitants from their homes and killing more than 53,000 people, according to Gaza health authorities.
