Israel launched a long-threatened ground offensive on Gaza City on Tuesday, escalating the two-year war with what Palestinians described as the heaviest bombardment yet.

The Israel Defence Forces (IDF) confirmed troops were moving deeper into the enclave’s main city, with numbers expected to rise in the coming days to confront what it estimates are 3,000 remaining Hamas fighters.

“Gaza is burning,” Defence Minister Israel Katz wrote on X, adding that Israeli troops were “fighting bravely to create the conditions for the release of the hostages and the defeat of Hamas.”

The push came despite warnings from European leaders who threatened sanctions, and concerns from some Israeli commanders that the campaign could prove a costly misstep.

The assault also followed a damning United Nations Commission of Inquiry report that accused Israel of committing genocide in Gaza, citing statements by top officials including Prime Minister Benjamin Netanyahu. Israel dismissed the findings as “scandalous” and “fake.”

Gaza’s health ministry reported at least 40 people killed in the early hours of Tuesday’s offensive, most in Gaza City. Airstrikes pounded residential neighborhoods as tanks pushed into the urban center.

Footage showed rescue workers and residents digging frantically through the rubble of two collapsed apartment blocks destroyed overnight. A woman wailed as the body of a child was retrieved, wrapped in a blanket and carried away.

The IDF renewed its calls for civilians to evacuate. Long streams of Palestinians fled south and west, carrying belongings in donkey carts, rickshaws, trucks, and on foot, as explosions echoed behind them.