The Israeli military issued forced evacuation orders to Palestinians, telling them to flee towns and cities in border areas, and said its troops had retaken control of parts of the so-called Netzarim corridor, which in effect splits Gaza between north and south.

The latest offensive brought an end to the fragile, two-month ceasefire in which Hamas released more than two dozen hostages and Israel pulled back from large parts of the strip.

The multiphase deal, which was meant to lead to a permanent end to the war and the freedom of the remaining captives, broke down after Israel made new demands of Hamas.

Netanyahu earlier this month ordered a full siege of Gaza and blamed the group for refusing to accept a new, tougher proposal to release up front many of its remaining 59 hostages — of whom roughly two dozen are believed to still be alive — without agreeing to end the war.

The imposition of the siege ended the surge of humanitarian aid that was a precondition of the ceasefire, which started around the time of US President Donald Trump’s inauguration in late January.

Israel also shut off the last remaining electricity line into the besieged enclave, which forced the closure of a desalination plant, worsening a shortage of clean water for Gaza’s population of 2.2mn.

Local health officials say that more than 48,000 people have been killed since Israel began its offensive in response to Hamas’s October 7 2023 attack, in which militants killed 1,200 people and took another 250 hostage.

While backed by the Trump administration, Israel’s renewed offensive and abandoning of the ceasefire talks has been condemned by Arab and some European countries. It also comes despite pleas by families of the hostages to keep negotiating for their release.

Separately, a European UN staff member was killed and five of his colleagues seriously wounded in an explosion at their accommodation in Deir al Balah in central Gaza, the UN Office for Project Services said.

UNOPS said it understood that a guesthouse in an isolated location — but repeatedly identified to IDF forces — was hit on Wednesday morning, after a similar incident the night before.

“An explosive ordnance was dropped or fired” at the installation and detonated inside it, according to the agency. A UN spokesman said it was too early to determine who was responsible for the attack. The Israel Defense Forces denied any role in the incident.

UNOPS executive director Jorge Moreira da Silva said he was “shocked and devastated”, adding: “What’s happening in Gaza is unconscionable.”