"The occupier (Israel) completely destroyed the cardiac department of Al-Shifa hospital... The two-storey building has been completely destroyed in an air strike," Youssef Abu Rish, deputy health minister in the Hamas-run Gaza Strip, told AFP.

Witnesses confirmed a strike on the hospital, which AFP was unable to independently verify.

The Israeli military did not immediately respond to a request for comment.

But it has previously denied deliberately targeting the hospital and has repeatedly accused Hamas of using medical facilities or tunnels underneath them as command centres and hideouts -- a charge Hamas denies.

An Israeli military statement on Sunday said soldiers "opened and secured a passage which enables the civilian population to evacuate, on foot and by ambulances, from the Shifa, Rantisi and Nasser hospitals."