Israel's army has begun its invasion of Gaza City after calling up 60,000 reservists, forcing Palestinians to flee the region.

Israel Defence Forces spokesman Brigadier General Effie Defrin said it now controls the outskirts of Gaza City, which was one of Hamas' last strongholds.

After a clash with Hamas fighters south of Khan Younis on Wednesday, he said 'We will deepen the blows to Hamas in Gaza City, a terror stronghold…

'We will deepen the blows to the terror infrastructure above and below ground, and disconnect the reliance of the population on Hamas.'

He added that the army 'is not waiting' and that 'preliminary operations are underway in the area' with Hamas now 'battered and bruised.'