The Israel-Hamas war entered its 200th day on Tuesday as aid groups warned that Israel's plans to invade the southern city of Rafah

Fears have been rising that Israeli Prime Minister Benjamin Netanyahu will soon follow through on repeated threats to send troops into Rafah, where 1.5 million people have sought shelter, many in makeshift encampments.

United Nations rights office said it was "horrified" at reports of mass graves found at the Gaza Strip's two biggest hospitals after Israeli sieges and raids.

Israel has repeatedly targeted Gazan medical facilities during the war, accusing Hamas of using them as command centres and to hold hostages abducted on October 7. Hamas denies the accusation.

Over the past three days, Gaza's Civil Defence agency said nearly 340 bodies were uncovered of people killed and buried by Israeli forces at the Nasser Hospital in the southern city of Khan Yunis.

Israel's army responded by saying that claims it had buried Palestinian bodies were "baseless and unfounded", without directly addressing allegations that Israeli troops were behind the killings.

The Israeli army carried out intense shelling overnight of Gaza City, AFP correspondents and witnesses said.

Shelling and loud explosions were heard in southwest Gaza and Khan Yunis city, while strikes hit the Bureij and Nuseirat refugee camps in central Gaza.

The war began with an unprecedented Hamas attack on October 7 that resulted in the death of around 1,170 people, according to an AFP tally of Israeli official figures.

In retaliation, Israel launched a military offensive that has killed at least 34,183 people in Gaza, mostly women and children, according to the health ministry in the Hamas-run territory.

The Israeli army announced the death of a soldier in Gaza, raising its toll to 261 since the ground operation began.