Israeli forces bombarded cities, towns and refugee camps across Gaza overnight and into Thursday, killing dozens of people in an air and ground offensive against Hamas that has widened to most of the territory and forced thousands more to flee from homes and shelters.

The war has already killed over 20,000 Palestinians and driven around 85 per cent of the population of 2.3 million from their homes. Much of northern Gaza has been leveled, largely depopulated and isolated from the rest of the territory for weeks. Many fear a similar fate awaits the south.