Israeli air strikes destroyed hundreds of buildings in the Gaza Strip overnight, the civil defence service in the Hamas-controlled Palestinian territory said on Saturday.

"Hundreds of buildings and houses were completely destroyed and thousands of other homes were damaged," said Mahmud Bassal, a spokesman for the Gaza Civil Defence.

The intense bombardments had "changed the landscape" of northern Gaza, he told AFP.

Witnesses said most of the bombing was concentrated on areas around two hospitals -- Al-Shifa and the so-called Indonesian hospital -- located in Jabaliya district of northern Gaza.

The strikes left wide craters in the streets and flattened many buildings in the area.

Just hours before Israel intensified its bombardment on Friday, army spokesman Daniel Hagari accused Hamas fighters of waging war on Israel from Gaza's hospitals and using civilians as "human shields".

The devastating conflict erupted after Hamas militants carried out a surprise cross-border attack on Israel on October 7 that left 1,400 people dead, many of them civilians, according to Israeli officials.

The Islamist group has also taken some 229 people to the Gaza Strip as captives, according to the army.

In retaliatory Israeli strikes, more than 7,300 people have been killed in the Gaza Strip, including some 3,000 children, according to the territory's health ministry. (AFP)