WATCH: Flares fall over Gaza as sun rises

Flares fall over the Gaza Strip as the sun rises on day 36 of the conflict between Israel and Hamas, as seen from Israel's Sderot.

The United Nations estimates tens of thousands of civilians remain in the fiercest battle zones in the north.

Hamas fighters smashed through the border on October 7, killing 1,200 people and taking 239 people hostage, according to updated Israeli figures.

Complicating Israel's military push is the fate of the hostages.

Four hostages have been freed so far by Hamas and another rescued in an Israeli operation. The desperate relatives of those still held in Gaza have piled pressure on Israeli and US authorities to secure the release of their loved ones.

The conflict has also stoked regional tensions, with cross-border exchanges between the Israeli army and Lebanon's Hezbollah.

Iran's Foreign Minister Hossein Amir-Abdollahian said the expansion of the Israel-Hamas war had become "inevitable".