Gaza's civil defence agency said Monday that the death toll had risen to 40 from overnight Israeli strikes that set ablaze tents of displaced Palestinians in Rafah, an attack that sparked condemnation across the Arab world.
Israel's army said the air strikes late Sunday, hours after a rocket attack had targeted Tel Aviv, had killed two senior Hamas operatives, and that it was investigating the reports of civilians killed in a fire.
The Israeli attack sparked strong protests from Egypt, Jordan, Kuwait and from Qatar which warned it could "hinder" budding steps to revive stalled truce and hostage release talks in the Israel-Hamas war raging since October 7.
Gaza's civil defence agency said Monday that many bodies were "charred" after the strikes triggered a fire that ripped through a displacement centre in northwest Rafah.
"The massacre committed by the Israeli occupation army in the refugee tents northwest of Rafah city in the southern Gaza Strip has left 40 martyrs and 65 wounded," said agency official Mohammad al-Mughayyir.
"We saw charred bodies and dismembered limbs ... We also saw cases of amputations, wounded children, women and the elderly."
Footage released by the Palestinian Red Crescent Society showed chaotic night-time scenes of paramedics in ambulances racing to the fiery attack site and evacuating the wounded, including children.
"We had just done with the evening prayers," recalled one survivor, a Palestinian woman who declined to be named.
"Our children were asleep ... suddenly we heard a loud sound and there was fire all around us. The children were screaming ... the sound was terrifying."
The ICRC said that one of its field hospitals was receiving an "influx of casualties seeking care for injuries and burns" and that "our teams are doing their best to save lives".
AFP images after sunrise showed the charred remains of makeshift tents and vehicles as Palestinian families looked at the blackened destruction.
Israel's army had said overnight that its aircraft had "struck a Hamas compound in Rafah", killing Yassin Rabia and Khaled Nagar, both senior officials for the Palestinian militant group in the occupied West Bank.
It added that it was "aware of reports indicating that as a result of the strike and fire that was ignited, several civilians in the area were harmed. The incident is under review."
Mughayyir said the rescue efforts were hampered by war damage and the impacts of Israel's siege on the territory amid the over seven-months-old conflict.
"There is a fuel shortage ... there are roads that have been destroyed, which hinders the movement of civil defence vehicles in these targeted areas," he said. "There is also a shortage of water to extinguish fires."
- 'Dangerous violation' -
Egypt deplored the "targeting of defenceless civilians" and labelled it part of "a systematic policy aimed at widening the scope of death and destruction in the Gaza Strip to make it uninhabitable".
Jordan also expressed its condemnation, accusing Israel of committing "ongoing war crimes".
Kuwait charged the attack exposed Israel's "blatant war crimes and unprecedented genocide to the whole world".
And Qatar condemned the Israeli bombing as a "dangerous violation of international law".
The strike came hours after Hamas had on Sunday, for the first time in months, launched a barrage of rockets at Tel Aviv and other areas of central Israel, sending people running into bomb shelters.
Although Israeli air defences took out most of the rockets and no casualties were reported, the attack was seen as an effort by Hamas to signal that it remains undefeated.
Hamas's armed wing said it had targeted Tel Aviv "with a large rocket barrage in response to the Zionist massacres against civilians".
Israel invaded Gaza in late October, but its ground forces are still battling Hamas in northern and central areas where Hamas has regrouped, as well as around Rafah.
Israel's top ally the United States has strongly urged all sides to resume truce talks, with efforts underway in recent days toward new talks with US, Egyptian and Qatari mediators.
After the latest violence, Qatar's foreign ministry voiced "concern that the bombing will complicate ongoing mediation efforts and hinder reaching an agreement for an immediate and permanent ceasefire".
Hamas said, after the overnight strikes, that Palestinians must "rise up and march".
- 'Justice for the Palestinians' -
The October 7 attack on southern Israel resulted in the deaths of more than 1,170 people, mostly civilians, according to an AFP tally based on Israeli official figures.
Militants also took 252 hostages, 121 of whom remain in Gaza, including 37 the army says are dead.
Israel's retaliatory offensive has killed at least 35,984 people in Gaza, mostly civilians, according to the Hamas-run territory's health ministry.
The Israeli military said Monday that its jets had over the past 24 hours struck and destroyed "over 75 terror targets" across the Gaza Strip.
The United Nations has warned of looming famine in besieged Gaza, where most hospitals are no longer functioning.
The bloodiest ever Gaza war and the spiralling civilian death toll have sparked a growing global backlash against Israel, including cases before two international courts in The Hague.
On Tuesday, Spain, Ireland and Norway are due to formally recognise a Palestinian state -- a step so far taken by more than 140 UN members but few western powers.
Israel, which charges the move amounts to "rewarding terrorism", on Monday announced punitive steps against Madrid, ordering its consulate in Jerusalem to stop offering consular services to Palestinians from June 1.
Foreign Minister Israel Katz said that "whoever gives an award to Hamas and tries to establish a Palestinian terrorist state will not be in contact with the Palestinians".
Spain's Foreign Minister Jose Manuel Albares had on Sunday said Madrid saw recognition of statehood as bringing "justice for the Palestinian people (and) the best guarantee of security for Israel".