The Israeli government formally declared war and authorized "significant military steps" to retaliate against Hamas for its surprise attack. The death toll exceeded 1,100, with thousands wounded on both sides.

Over 40 hours after the attack, Israeli forces were still battling militants in southern towns and escalating bombardments of Gaza. Hamas claimed to have captured over 130 people from inside Israel, intending to trade them for Palestinian prisoners.

Israeli forces aimed to regain control of areas seized by Hamas, including two kibbutzim. Footage showed intense exchanges of fire. The declaration of war indicated more fighting, and a question arose regarding a potential ground assault into Gaza.

In Gaza, airstrikes flattened residential buildings, causing civilian casualties. Thousands were displaced, and UNRWA reported that a school sheltering 225 people was hit.

In northern Israel, Hezbollah briefly exchanged strikes with Israel, sparking fears of a wider regional conflict. The situation calmed after the exchange.

The Israeli Security Cabinet's declaration of war on Hamas was symbolic but signaled a significant escalation. It also authorized "significant military steps" with the goal of preventing future threats.

The Hamas assault revealed intelligence gaps and challenged the perception that Israel had complete control over Gaza.

Hostages in Gaza complicated the situation, and Egypt offered assistance in securing their safety. Egypt also discussed a potential cease-fire, which Israel declined.

Clashes in the West Bank resulted in six Palestinian deaths. Israel's settlement expansion and settler violence in the West Bank, as well as tensions around the Al-Aqsa mosque, have contributed to regional instability.

In summary, Israel declared war on Hamas following their attack, with ongoing fighting and escalating casualties. Hostages in Gaza and regional tensions added complexity to the situation, raising concerns of a wider conflict.