An Israeli airstrike in northern Gaza has killed at least 20 people, mostly women and children, Palestinian officials said Tuesday, as Israel wages a nearly monthlong air and ground operation in what was already the most isolated and heavily destroyed part of the territory.

At least 90 people were killed in northern Gaza on Tuesday after an Israeli airstrike hit a five-story building in the residential neighborhood of Beit Lahiya. At least 25 of them were children. CNN’s Katie Polglase reports on Israel’s intensifying bombing campaign on the north of the Gaza strip.

The health ministry in Hamas-run Gaza said Monday Israeli forces are bombarding the last partially functioning hospital in north Gaza, an area of intense military operations for the past month.The Israeli military is engaged in intense military operations in the north of the Palestinian territory where it says Hamas militants have regrouped.

Hamas-run Gaza's health ministry said Monday Israeli forces were bombarding the last partially functioning hospital in the territory's north, as Israel formally notified the UN it is cutting ties with the main aid agency for Palestinians.

As Israeli troops encircle Gaza City and press ahead with a ground offensive, the death toll is expected to grow. BUREIJ REFUGEE CAMP: The grey film covering the faces of children rushed to Al-Aqsa Hospital in central Gaza Thursday made it hard to distinguish between the living and the dead.

The health ministry in Hamas-run Gaza said Monday that Israeli forces are bombarding the last partially functioning hospital in north Gaza, the area of intense Israeli military operations for the past month.