Gaza's civil defence agency reported that Israeli air strikes since dawn on Sunday have killed at least 25 Palestinians across the Gaza Strip, including women and children.

Israel resumed its aerial and ground assault on Gaza on March 18, reigniting fighting after a two-month ceasefire that had paused more than 15 months of war in the coastal territory.

"Since dawn today, the occupation's air strikes have killed 20 people and injured dozens more, including children and women across the Gaza Strip," said Mahmud Bassal, spokesman for the civil defence agency.

In a separate statement later, the agency reported that five people were killed in an Israeli drone strike on a group of civilians in eastern Rafah.

Israeli Prime Minister Benjamin Netanyahu on Saturday vowed to continue the war and bring home the remaining hostages held in Gaza without yielding to Hamas's demands.

"We are at a critical stage of the campaign, and at this point, we need patience and determination to win," Netanyahu said in a statement, rejecting calls from the militants to end the war and withdraw troops from Gaza.

Meanwhile, dozens of protesters clashed with police on Saturday in the central Israeli community of Mazor, where Netanyahu was expected to visit, vocing their anger at their leader and demanding an end to the war.

Since Israel resumed its offensive last month, at least 1,827 people have been killed in Gaza, according to the territory's health ministry.

The overall death toll in the Gaza war has reached 51,201, the majority of them civilians, according to the ministry, figures the UN considers reliable. (Agencies)