Destroyed buildings caused by the ongoing Israeli airstrikes on Gaza City on Saturday. AP

Israel entered a new phase of its war on Hamas on Saturday, expanding its ground attacks after blacking out nearly all communication in the Gaza Strip with increased bombardment and artillery fire. Prime Minister Benjamin Netanyahu called it a war for Israel's existence, and said "'Never again' is now.”

Gaza residents described the massive bombardment from the land, air and sea as the most intense of the 3-week-old Israel-Hamas war. It knocked out most communications in the territory late Friday and largely cut off the besieged enclave’s 2.3 million people from the world.

Communications were restored to many people in Gaza early Sunday, according to the telecoms company Paltel, Internet-access advocacy group NetBlocks.org and confirmation on the ground.

The Palestinian death toll passed 7,700, most of them women and children, according to the Health Ministry in Hamas-ruled Gaza. In the occupied West Bank, more than 110 Palestinians have been killed in violence and Israeli raids.

More than 1,400 people were slain in Israel during a surprise incursion by Hamas, including at least 310 soldiers, according to the Israeli government. At least 229 hostages were taken into Gaza, and four hostages have been released.

Israeli Prime Minister Benjamin Netanyahu speaks during a press conference in Tel Aviv on Saturday. AFP

The United Nations said thousands more civilians could die in Gaza as Israel announced the war had entered a "second stage", with ground forces still operating inside the Hamas-run territory more than 24 hours after entering it on Friday.

Israeli fighter jets meanwhile dropped leaflets over Gaza City warning residents that the area was now a "battlefield", that shelters in northern Gaza were not safe, and they should "evacuate immediately" to the south.

Thousands more could die

The army delivered similar warnings earlier in its campaign, but many who fled south have returned home after failing to find refuge from Israeli bombing.

UN human rights chief Volker Turk has warned of "the possibly catastrophic consequences of large-scale ground operations in Gaza", saying "thousands more civilians" could die.

And as Israel sends troops and tanks further into Gaza, analysts cautioned of possible fallout threatening the entire Middle East, even as Western fears grow that Iran-backed Hezbollah could open a new front on the Lebanese border.

A UN peacekeeper was injured Saturday by shelling in south Lebanon, the mission's spokesman said, hours after reporting a hit at its headquarters as Israel-Lebanon border skirmishes intensify.

Agencies