As Israeli soldiers in tanks and bulldozers dug in across a mile-wide strip of Gaza's eastern frontier, Palestinian officials said military strikes had now killed more than 300 people, most of them civilians.
On Thursday, after 10 days of air and naval barrages, Israel launched a ground offensive with military engineers concentrating on a bufferzone 1.5 miles wide. The troops were looking to destroy tunnels and concealed rocket launch pads dug by Gaza's dominant Hamas group after the last big flare-up of violence in 2012.
Hamas said its fighters used a tunnel to slip into Israel yesterday, inflicting casualties. The Israeli military confirmed the incident, saying it killed one militant. It also said two Israeli soldiers had been killed.
Israeli military spokesman Lieutenant Colonel Peter Lerner said: "We have struck hard on the two main strategic assets of Hamas - the rockets and these tunnels."
Palestinian militants also fired at least 18 rockets into Israel yesterday, killing one man and wounding four people, including two children, in the southern town of Dimona, police said.
According to Gaza officials, at least 318 Palestinians, including 70 children, have been killed in the 12-day conflict. Attacks overnight on Friday from Israel killed 26 Palestinians, mostly civilians, in the northern towns of Beit Hanoun and Beit Lahiya and in Khan Younis in the south.
"I live in fear expecting death. I no longer know what's more difficult - to die or to await death," said Ali Mahmoud, 40, a resident of Beit Hanoun, from where the Israeli ground action could be heard just 800 yards away.
In Khan Younis, paramedic Khamis Shaath rushed to attend to casualties, and discovered two of the dead were his nephews. His wife and son had been wounded. Collapsing with grief, he had to be taken to a hospital himself, colleagues said.
The sound of tank fire and heavy machine guns mixed with the mosques' call to prayer along the Gaza-Israel border. The escalation of hostilities and the toll on Gaza's 1.8 million Palestinians has been profound. Officials estimated that 90% of Gaza's electricity supply had been cut off by Israel.
But the Israeli onslaught appears only to have hardened the resolve of some Palestinian fighters resisting the ground offensive.
Hamas spokesman Sami Abu Zuhri said: "There will be no truce without an end to the war that the Occupation [Israel] began, a lifting of the blockade and a halt to all violations and killings in Gaza and the West Bank."
United Nations Secretary-General Ban Ki-moon planned to travel to Israel and the Palestinian territories this weekend.
At an emergency session of the UN Security Council on Friday, UN political affairs chief Jeffrey Feltman condemned the rocket attacks from Gaza, but voiced alarm at "Israel's heavy response".
The UN said that more than 50,000 Palestinians have taken refuge from the Israeli attacks in its Gaza shelters.
"One or two days of F-16 strikes on our neighbourhood and we'd had enough," Ahmed Abdel-Ahad, 42, said at a UN school in northern Jabalya, where he was camped out with his family.
US-backed Palestinian president Mahmoud Abbas, who entered a power-sharing deal with his Islamist rivals in April, has been shuttling between Egypt and Turkey in search of a breakthrough.
However, Turkey serving as an intermediary looked unlikely after Israel pared down its diplomatic missions in Ankara and Istanbul this week following sometimes violent pro-Palestinian street protests and what Israel deemed "incitement" by the Islamist-rooted Turkish prime minister Tayyip Erdogan.
Yesterday, the foreign ministry in Jerusalem advised Israelis to avoid "non-essential" travel to Turkey.