Palestinian negotiators have warned they will leave Cairo on Sunday unless Israel agrees to return to Egyptian-mediated negotiations to end the fighting in Gaza without setting conditions.

"We told the Egyptians that if the Israelis are not coming and if there is no significant development, we are leaving today," Palestinian negotiator Bassam Salhi told the Associated Press on Sunday.

Al Jazeera's Andrew Simmons, reporting from Gaza City, however, said that there were also reports that a new 72-hour truce is also being considered.

"How it will work is not clear," our correspondent said. "But there is a positive word coming out."

Palestinian representatives including Hamas have been demanding that Israel lift the blockade. But Israel said it will not take part in truce talks while violence is ongoing.

"Israel will not negotiate under fire," Israeli Prime Minister Benjamin Netanyahu said in broadcast remarks at the weekly meeting of his cabinet, in Tel Aviv.

"The operation will continue until its objective - the restoration of quiet over a protraced period - is achieved. I said at the beginning and throughout the operation - it will take time, and stamina is required."

Netanyahu's comments came as Israeli air strikes killed at least four people in Gaza on Sunday. Among those killed were a 14-year old boy and a woman, medics said.

Al Jazeera also learned that one person was killed in the southern district of Rafah, and another person in Beit Hanoun.

As of Sunday afternoon, the death toll in Gaza has reached 1,917, and 449 of them were children. According to the UN, about 73 percent of the people killed were civilians.

A total of 64 Israeli soldiers were also killed and three civilians on the Israel side.

Netanyahu under pressure

Reporting from West Jerusalem, Al Jazeera's Nisreen El-Shamayleh said that Netanyahu has come under a lot of pressure internationally and domestically.

"Internally, people are frustrated especially those who live in the south who had evacuated their homes along the border with Gaza for a month and then were told to return home during the ceasefire only to find out fighting has resumed, she said.

"He is also under pressure from the international community to return to Cairo for talks."

The Israeli delegation was locked in talks over "all the developments," an official told AFP, without ruling out the possibility the team could return to Cairo.

"The delegation is sitting together to discuss all the developments," he said on Sunday. "If they do, it will be this evening or tomorrow."

Meanwhile, Al Jazeera's Kimberly Halkett, reporting from West Jerusalem, said that the Palestinian delegation in Cairo is set to meet with Arab League representatives on Monday to discuss the proposed truce.

So far, Egyptian efforts to broker an end to more than a month of fighting have led nowhere, with Israel pulling its team out of talks in Cairo on Friday after Hamas refused to extend a 72-hour ceasefire which had brought relief to millions on both sides of the border.

On Saturday, Israel launched more than 30 air attacks in Gaza on Saturday, killing nine Palestinians, and Palestinian fighters fired rockets at Israel as the conflict entered a second month.

An Israeli military statement said four of the Palestinians targeted on Saturday were Hamas fighters.