Israel estimates that its imminent offensive on Gaza City would displace one million Palestinians, a senior military official has said, as Gaza’s civil defence reported dozens killed across the territory, Reuters reports.

Israel’s military has been building up its forces for the planned operation to seize Gaza City, the Palestinian territory’s largest urban centre located in its northern part, despite mounting global concern for Palestinian civilians suffering dire humanitarian conditions.

Military chief Eyal Zamir said troops were already “intensifying our combat operations”, according to an army statement.

The senior official from COGAT, the Israeli defence ministry body that oversees civil affairs in the Palestinian territories, said “approximately 70,000” Palestinians had already left Gaza’s north in recent days, fleeing the Israeli advance.

Briefing journalists on condition of anonymity, the official said Israeli authorities expected “a million people” to flee south, without giving a specific timeframe.