Israel's self-declared "second phase" of a three-week war against Iranian-backed Hamas militants had initially been kept from public view, with forces moving under darkness and a telecommunications blackout cutting off Palestinians.
The phone and internet cuts appeared to be easing on Sunday, according to Gaza residents. But they have severely hampered rescue operations for casualties of Israeli barrages wreaking destruction, especially on northern Gaza City, site of Hamas' government and command centres.
As well as the Israeli military's pictures of tanks, some images online appeared to show Israeli soldiers waving an Israeli flag deep inside Gaza.
Reuters could not verify those images.
Hamas said it was firing mortars against Israeli forces in north Gaza and had hit Israeli tanks with missiles, belittling reports of deep advances by its enemy.
"Israel cut us off from the world in order to wipe us out, but we are hearing the sounds of explosions and we are proud the resistance fighters have stopped them at metres distance," said Shaban Ahmed, a public servant who stayed in Gaza City despite an Israeli warning to evacuate south.
Ahmed said he only found out yestertday that his cousin had died in an air strike two days previously due to the blackout.
Israeli Defence Force (IDF) fighter jets struck over 450 Hamas targets, including operational command centres, look-out posts, and anti-tank missile launch posts, in the last 24 hours, the military said on Sunday.
It said several gunmen emerged from a tunnel near Israel's border and were killed or wounded in a clash with troops.
"We are gradually expanding the ground activity and the scope of our forces in the Gaza Strip," said IDF spokesperson Rear Admiral Daniel Hagari.
Israel has tightened its blockade and bombarded Gaza since Hamas gunmen stormed across the border into Israel on Oct. 7, killing at least 1,400 people and taking more than 200 hostages.
International Criminal Court prosecutor Karim Khan visited the Rafah crossing where he said blocking relief for innocent civilians could constitute a crime and urged Israel to cooperate.
Western countries have generally backed what they say is Israel's right to self-defence. But there has been mounting international outcry for a "humanitarian pause" to allow aid in.
Israel will allow a dramatic increase in aid to Gaza in coming days and Palestinian civilians should head to a "humanitarian zone" in the south of the tiny territory, said Colonel Elad Goren of Cogat, the Israeli Defence Ministry agency that coordinates with the Palestinians.
Medical authorities in the Gaza Strip, which has a population of 2.3 million people, said 8,005 people - including 3,324 minors - had been killed.
The Hamas-run Gaza government's media office said 116 medics and 35 journalists have been killed since the conflict erupted.
Reuters was unable to independently verify.
Israel has vowed to annihilate Hamas, a task that it described as necessitating protracted ground assaults in, around and under Gaza City, where the militants have an extensive subterranean bunker network.
There are fears too of regional overspill to the Gaza war, including in Lebanon where the Israeli army and Iranian-backed Hezbollah group have been exchanging fire.
On Sunday, the United Nations' Lebanon peacekeeping force UNIFIL said one of its members was injured after shells hit the mission's base near Houla on the Lebanese-Israeli border the day before.
Israel said there were several rocket or mortar launches from Lebanon at its territory, and that it was returning fire, while Hezbollah said it shot down an Israeli drone.
White House national security adviser Jake Sullivan told CNN that Israel must use every means possible to distinguish between Palestinian civilians and Hamas in Gaza. He also urged Israeli Prime Minister Benjamin Netanyahu to "rein in" violence against innocent people in the occupied West Bank.
With supplies of food, water and medicines running low and much of Gaza reduced to rubble, thousands of residents broke into warehouses and distribution centres of the United Nations Palestinian refugee agency (UNRWA), grabbing flour and other basics, the organisation said.
The Palestinian Red Crescent said 10 Egyptian trucks carrying food and medicine had arrived in Gaza via the Rafah crossing, bringing the total number so far to 94, a small fraction of what is needed.
Displaced Palestinians staying in tents in Gaza’s Khan Younis described dire living conditions, with little access to food and water and having to queue hours for the toilet.
"I wish God will have mercy on us and the war stops," said Rami Al-Erqan, a father cradling his daughter, one of his six children. "We reached a state where we wish to have died under the rubble just to find some rest. Our life is torture."
Central Israel also came under heavy rocket fire on Sunday, with sirens sounding in several major cities.
Al-Qassam Brigades, the armed wing of Hamas, said it was bombing Tel Aviv. They later said their fighters had clashed with Israeli forces northwest of Gaza and had also set fire to two Israeli tanks. There was no word from Israel on the claims.
The conflict has prompted large demonstrations worldwide in support of the Palestinians. On Sunday several thousand people rallied in Beirut to show solidarity with Gaza.
The Palestinian Red Crescent said it had received warnings from Israeli authorities to immediately evacuate al-Quds hospital in the Gaza Strip, adding that raids conducted on Sunday had taken place just 50 metres from the facility.
The Red Crescent says some 14,000 people have sought shelter at the hospital. Israel has accused Hamas of locating command centres and other military infrastructure in Gaza hospitals, something the group denies.
Palestinian officials said around 50,000 people had also taken shelter in the Gaza Shifa Hospital and said they were concerned about ongoing Israeli threats to the facility.
