Palestinian protesters burn tyres following a demonstration. File/AFP

At least 12 Palestinians, including two children and a woman, were killed early on Saturday morning by Israeli attacks east of Gaza's Khan Younis and in the Al-Nuseirat camp area, the official Palestinian news agency Wafa said.

At least 15 others were injured in the attacks, Wafa added.

Meanwhile, Egyptian President Abdel Fattah al-Sisi and US President Joe Biden, in a phone call, emphasized the importance of Israel and Hamas showing flexibility in negotiations over a Gaza ceasefire-for-hostages deal, the Egyptian presidency said on Friday.

Secretary of State Antony Blinken visited the Middle East this week and said that Israeli Prime Minister Benjamin Netanyahu was onboard with a US proposal to bridge gaps on the ceasefire.

Kirby said that the United States continued to believe that Netanyahu accepted the proposal, even though the right-wing leader has insisted on Israeli troops staying on the Gaza-Egypt border, butting heads with both Washington and Cairo.

At least 15 others were injured in the attacks.

Kirby appealed again to Hamas to accept the proposal, which was laid out last week in talks in the Qatari capital Doha.

"Think about what this deal will do for the people of Gaza. It gets them a period of calm and a potential end of the war and the violence and the bloodshed," Kirby said.

"It also gets them, because of the stop in the fighting, an incredible opportunity for all of us — and I mean all of us, including the United States — to dramatically increase the humanitarian assistance that's getting in," he said.

Agencies