Thousands of Israeli troops, backed by tanks, warplanes and gunboats, pressed deeper into the Gaza Strip on Friday as Palestinian militants returned fire with rockets and mortar rounds and terrified residents hunkered down in their homes.
Israel launched the ground offensive late Thursday after 10 days of aerial bombardments failed to halt the rocket fire raining down on Israeli cities and towns from the coastal enclave, which is controlled by the Hamas militant group.
Heavy fighting was reported overnight in the northern Gaza cities of Beit Hanoun and Beit Lahia, as well as around Khan Younis and Rafah to the south. Loud explosions continued throughout the day, as ambulances cruised the streets searching for victims.
At least 28 Palestinians have been killed since the ground operation began, according to Gaza health officials quoted by the Maan news agency. They include three siblings from 13 to 15 who died when their house in Beit Lahia was shelled. A separate attack killed nine members of an extended family in Khan Younis, the news service reported.
The Israeli military said 17 militants were killed since the ground operation was launched, and 13 others surrendered and were taken for questioning. An Israeli soldier was also killed and two were injured, the military said. The cause of the death was under investigation, but Israeli media reported that friendly fire was suspected.
The sharp escalation in the fighting came despite growing international pressure on the two sides to suspend hostilities that have claimed more than 260 lives, most of them Palestinian civilians.
Israel accepted an Egyptian cease-fire proposal this week that called on the parties to wind down the fighting and send negotiators to Cairo to hammer out a more permanent truce.
But Hamas officials did not accept the agreement, saying the militia won't back down until its key demands are met. They include the lifting of a crippling blockade on the impoverished territory, the reopening of border crossings into Israel and Egypt, and the release of members jailed in the West Bank during recent sweeps spurred by the slaying of three Israeli teens.
The Israeli ground campaign appeared to be limited in scope, targeting a network of tunnels that Hamas and its allies use to smuggle weapons and fighters into Israel.
But Prime Minister Benjamin Netanyahu told reporters he had instructed the military to prepare for the possibility of a "considerable expansion of the ground operation.”
"We chose to embark on this operation after exhausting the other options and with the understanding that without the operation, we could pay a much higher price,” Netanyahu said as he headed into a Cabinet meeting Friday.
Hamas spokesmen called it a dangerous decision and said they were prepared to fight back. Scores of rockets were fired Friday into southern and central Israel.
As morning broke, families living in Gaza's frontier areas piled into donkey carts and fled for the interior, squeezing in with relatives or joining some 22,000 people sheltering at United Nations-run schools and other facilities.
Others, however, were too afraid to leave their homes.
"Where to go?" lamented Sharhabeel Mahmoum, a 37-year-old pharmacist and father of four reached by telephone in Beit Lahia. "As long as Israeli planes are in the air, there is no safe place."
Times staff writer Zavis reported from Ashkelon and special correspondent Sobelman from Jerusalem. Times photographer Carolyn Cole in Gaza City contributed to the report.
For more news from Israel and the Gaza Strip, follow @alexzavis on Twitter