At least 70 Palestinians were killed, 200 others were injured after Israel launched attacks on Khan Younis, which is designated as a safe zone, as it ordered displaced Palestinians in the area to relocate once again.

"Due to the Israeli occupation's attacks and massacres in Khan Younis governorate from the early hours of this morning until now, 70 people have been martyred and more than 200 wounded," the health ministry in Gaza said in a statement.

Thousands of Gazans fled an Israeli-designated humanitarian zone Monday after the army ordered them to leave and warned of attacks, even though Palestinians have nowhere else to flee.

Israeli Prime Minister Benjamin Netanyahu, who is accused of war crimes and genocide, was on his way to Washington to deliver a speech at what he said was a time of "great political uncertainty", following U.S. President Joe Biden's decision not to seek re-election.

Netanyahu will meet Biden, who has pushed him to agree to a cease-fire with Hamas, more than nine months into the Gaza war.

Fighting raged in Gaza as the Israeli military ordered Palestinians to evacuate part of a humanitarian zone, just two months after directing them there for their own safety.

The military said it issued the order to leave the eastern Khan Younis sector of the Al-Mawasi humanitarian zone as it was "about to forcefully operate" to curb rocket fire.

Facing yet another displacement, Palestinians filled the dusty streets of Khan Younis with cars, motorbikes, donkey-drawn carts, and on foot, carrying what belongings they could.

Hassan Qudayh said his family fled in "panic."

"We were happily making breakfast for our children, as we had been safe for a month, only to be stunned by shells, warning leaflets and martyrs in the streets," he told AFPTV.

"This is the 14th or 15th time we've been displaced.

"We want peace, not war. We want to be united. Enough! We've been suffering for 10 months."

Israel's relentless attacks have plunged Gaza into a severe humanitarian crisis.

Yussef Abu Taimah from Al-Qarara in Khan Younis said his family went to the humanitarian zone but found no space.

"Even the sidewalks are full of people and tents. We are tired and fed up. Enough of this displacement and migration".

In the scorching summer heat, Palestinians at the Jabalia refugee camp in northern Gaza scoured ruins for water needed for drinking, bathing, and laundry.

For the Shanbari family, water is so precious they try not to spill a single drop.

Exhausted from the constant struggle for basics, the parents say their children are sick.

"All my children have fallen ill -- they're suffering from kidney failure, jaundice, itching, and cough," said Ahmed al-Shanbari. "I don't know what to say, and there aren't even any medicines available."

Nearby, huge sewage puddles, sometimes pond-sized, cover the roads.

On the diplomatic front, months of intermittent talks for the first cease-fire and hostage-prisoner swap since November have yielded little progress.

Netanyahu will meet Biden on Tuesday and deliver a speech to Congress on Wednesday, amid unprecedented strains between Israel and its ally the United States.

The Israeli leader has repeatedly resisted pressure from the Biden administration to accept a truce.

Washington fears a voter backlash over the mounting civilian war toll in Gaza, while protests by anti-government demonstrators and families of hostages in Israel are pressuring Netanyahu.

"Never before has the atmosphere been so fraught," said Steven Cook, a Middle East specialist at the Council on Foreign Relations.

"There is clearly tension in the relationship, especially between the White House and the Israeli prime minister," Cook said in a commentary.

The visit comes as Israel tries to extend the war throughout the region.

Israel on Saturday attacked Yemen for the first time, in retaliation for a deadly drone strike on Tel Aviv by the Iran-backed Houthi rebels.

There were also further exchanges of fire between Lebanon's Iran-backed Hezbollah movement and the Israeli military at the weekend, as tensions remained high along the border.

On Sunday, Netanyahu's office said he was sending a negotiating team for new talks on a truce deal. He said the delegation would leave on Thursday, but it remains unclear where it will go.

Egypt, Qatar and the United States have been working unsuccessfully for months to secure a deal between Israel and Hamas.