Israel's military kept up its assault on Gaza City and the wider Gaza Strip on Saturday, dismantling underground shafts and booby-trapped structures in attacks that killed at least 60 Palestinians, according to Gaza's health authorities.

The assault came as 10 countries, including Australia, Belgium, Britain and Canada, are scheduled to formally recognize an independent Palestinian state on Monday, ahead of the annual leaders' gathering at the UN General Assembly next week.

Israeli forces, which control Gaza City's eastern suburbs, have been pounding the Sheikh Radwan and Tel Al-Hawa areas from where they would be positioned to advance on central and western parts of the city. Most of Gaza City's population is sheltering in those parts.

The military estimates that it has demolished up to 20 Gaza City tower blocks over the past two weeks. According to Israeli media, it also believes that more than 500,000 people have left the city since the start of September.

The militant group Hamas, which controls Gaza, disputes this, saying just under 300,000 have left and around 900,000 remain, including Israeli hostages.

Hamas also estimates that since August 11, Israel's military has destroyed or damaged more than 1,800 residential buildings in Gaza City and destroyed more than 13,000 tents housing displaced families.

In almost two years of fighting, Israel's offensive has killed more than 65,000 Palestinians, according to Gaza's health authorities, spread famine, demolished most structures and displaced most of the population, in many cases multiple times.

Israel says the hunger crisis in Gaza has been exaggerated and that much of the blame lies with Hamas.

(With input from agencies)