The EU on Sunday condemned Hamas for using "hospitals and civilians as human shields" in Gaza, while also urging Israel to show "maximum restraint" to protect civilians from the war it is waging.

"The EU is gravely concerned about the deepening humanitarian crisis in Gaza," EU foreign policy chief Josep Borrell said in a statement.

The appeal went out as Gaza's largest medical facility, Al-Shifa hospital, was being targeted for repeated strikes. Hamas health officials said one of them destroyed its cardiac ward on Sunday.

Another facility, Al-Quds hospital, was knocked out of service because of a lack of generator fuel, the Palestinian Red Crescent said.

Israel denies deliberately targeting hospitals. It accuses Hamas of using the facilities, or tunnels under them, as hideouts, which the Islamist militant group denies.

"These hostilities are severely impacting hospitals and taking a horrific toll on civilians and medical staff," the EU statement said.

"The EU emphasises that international humanitarian law stipulates that hospitals, medical supplies and civilians inside hospitals must be protected.

"Hospitals must also be supplied immediately with the most urgent medical supplies and patients that require urgent medical care need to be evacuated safely. In this context, we urge Israel to exercise maximum restraint to ensure the protection of civilians."

"The EU condemns the use of hospitals and civilians as human shields by Hamas," the statement said.

It reiterated Brussels' stance that Israel has a "right to defend itself in line with international law and international humanitarian law".

The EU called for speedy and "unhindered" humanitarian access so aid can reach Gazans suffering under more than a month of bombardment, displacement and extremely limited water, food, fuel and shelter.

It called on Hamas to release the  240 hostages its militants took captive during the October 7 attack on Israeli communities close to Gaza, and said it was "crucial" that the International Committee of the Red Cross be given access to the hostages.

"The EU joins calls for immediate pauses in hostilities and the establishment of humanitarian corridors," it said.

The bloodiest ever Gaza war broke out after Hamas on October 7, killing around 1,200 people, mostly civilians, according to Israeli figures.

Israel's relentless campaign in response has killed at least 11,180 people, also mostly civilians and including 4,609 children, according to the Hamas government's media office.