Israeli tanks pushed deeper into Rafah on Tuesday, reaching some residential areas of the southern Gazan border city where more than a million people had sought shelter, and its forces pounded the enclave’s north in some of the fiercest attacks in months.

Israel’s international allies and aid groups have repeatedly warned against a ground incursion into Rafah, where many Palestinians fled and Israel says four Hamas battalions are holed up. Israel says it must root out the remaining fighters.

The White House said U.S. national security adviser Jake Sullivan will visit Israel and Saudi Arabia this weekend. The Biden administration declined to comment on a report by Axios that Israel agreed not to expand its Rafah operation significantly before Sullivan’s visit.

A U.S. official who declined to be identified told Reuters that Israel promised not to make a major move in Rafah without advising Washington.

Israeli spokesperson Rear Admiral Daniel Hagari said in a briefing that Israeli forces had killed about 100 fighters, located 10 tunnel routes and found many weapons in Rafah since the start of the operation a week ago.

“We are operating with determination in all three parts of the Gaza Strip. Forces from the air, land and sea are simultaneously striking terrorist targets,” Hagari said, referring to the enclave’s north, centre and south.

The Palestinian death toll in the war has now surpassed 35,000, according to Gaza health officials, whose figures do not differentiate between civilians and fighters. They said that 82 Palestinians had been killed in the past 24 hours, the highest death toll in a single day in many weeks.

Fierce gun battles raged late on Tuesday in northern Gaza’s Jabalia, a sprawling refugee camp built for displaced Palestinians 75 years ago. “Many people are being trapped in their houses,” Nasser, 57, a father of six, said by phone.

In Gaza City, also in the enclave’s north, an Israeli air strike on a house in the Sheikh Radwan neighbourhood killed four people and wounded several others late on Tuesday, medics said.

In the Zeitoun neighbourhood of Gaza City, Israeli bulldozers demolished houses to make a new road for tanks. The Israeli military said it had eliminated about 150 fighters and destroyed 80 structures used by Hamas there.

With fighting intensifying, Qatar’s Prime Minister Sheikh Mohammed bin Abdulrahman Al-Thani said ceasefire talks between Israel and Hamas, mediated by his country and Egypt, were at a stalemate.