Israel said it had "dismantled" Hamas's military leadership in northern Gaza as its war against the Palestinian group entered its fourth month Sunday, with fears mounting that the conflict could spread into neighboring Lebanon.

Witnesses said Israel carried out air strikes early Sunday in Gaza's main southern city of Khan Yunis, with the official Palestinian news agency Wafa reporting numerous dead and wounded.

Israel's army said late Saturday it had "completed the dismantling of the Hamas military framework in the northern Gaza Strip" and its forces would now focus on central and southern areas of the territory.

The prospect of a wider regional war loomed with army spokesman Daniel Hagari warning that Lebanon's Iran-backed Hezbollah group was "dragging Lebanon into an unnecessary war".

The group fired more than 60 rockets at an Israeli military base on Saturday in response to this week's killing in Beirut of Hamas's deputy leader.

The war in Gaza was triggered by an unprecedented attack on Israel launched by Hamas on 7 October, which resulted in the deaths of around 1,140 people, most of them civilians, according to an AFP tally based on official Israeli figures.

The militants also took around 250 hostages, 132 of whom remain in captivity, according to Israel, including at least 24 believed to have been killed.

In response, Israel is carrying out a relentless bombardment and ground invasion that have killed at least 22,722 people, according to the Hamas-run Gaza health ministry.

Israel's Prime Minister Benjamin Netanyahu vowed that Israel would continue its campaign to "eliminate Hamas, return our hostages, and ensure that Gaza will no longer be a threat to Israel".

Netanyahu was under growing pressure on Saturday with demonstrators gathering in Tel Aviv's Habima Square to call for early elections and the resignation of his government.

"Bibi Netanyahu and all the rest of his idiots are ruining Israel and they are destroying everything we hoped and dreamed of," Shachaf Netzer, 54, told AFP.