The organisation said it was reviewing claims more than 300 bodies were discovered at two different burial sites outside the Nasser and al-Shifa hospitals, some of whom were women and elderly people.

The UK has announced new sanctions against Iran’s drone and missile industry, Archie Mitchell reports.

Two people linked to the country’s network of drone production, Seyed Mohsen Vahabzadeh Moghadam and Abbas Abdi Asjerd, will be subject to a UK travel ban and asset freeze.

Four companies – Bonyan Danesh Shargh, Pishro Sanat Aseman Sharif Company, Alvand Motorbuilding Industries Company and Moj Gostar Aseman Parvaz Company – will also face a UK asset freeze.

Foreign Secretary Lord Cameron said: “The Iranian regime’s dangerous attack on Israel risked thousands of civilian casualties and wider escalation in the region.

“Today the UK and our partners have sent a clear message – we will hold those responsible for Iran’s destabilising behaviour to account.

“Alongside our partners, we will continue to tighten the net on Iran’s ability to develop and export these deadly weapons.”

A spokesperson for Israeli Prime Minister Benjamin Netanyahu said the military was moving ahead with its plans for a ground operation in Rafah as the Israeli military said that it had mobilised two more reservist brigades for missions in Gaza.

A Palestinian civil defence team on Thursday called on the United Nations to investigate what it said were war crimes at a Gaza hospital, saying nearly 400 bodies were recovered from mass graves after Israeli soldiers departed the complex.

“There are cases of field execution of some patients while undergoing surgeries and wearing surgical gowns at the Nasser Medical Complex,” the civil defence forces said at a press conference, without presenting any evidence.

Palestinian authorities have this week reported finding hundreds of bodies in mass graves at Nasser hospital, the main medical facility in central Gaza, after Israeli troops pulled out of the city of Khan Younis.

Bodies were also reported to have been found at the Al Shifa hospital in northern Gaza, which was targeted in an Israeli special forces operation.

UN rights chief Volker Turk said on Tuesday he was “horrified” by the destruction of the Nasser and Al Shifa medical facilities and by the reports of the mass graves, according to a spokesperson.

The Israeli military said claims by Palestinian authorities that the Israeli Defence Forces (IDF) had buried the bodies were “baseless and unfounded”.

A picture shows thick clouds of smoke billowing into the sky following an explosion amid Israeli strikes in southern Lebanon.

The image appears to show the aftermath of a strike on the village of Alma al-Shaab amid ongoing tensions on the border, exacerbated by the war in Gaza.

Palestinian hospital officials said Israeli airstrikes on the southern city of Rafah in the Gaza Strip killed at least five people.

More than half of the territory’s population of 2.3 million have sought refuge in Rafah, where Israel has conducted near-daily raids as it prepares for an offensive in the city.

In central Gaza, four people were killed in Israeli tank shelling.