Heavy clashes took place at dawn Friday between resistance fighters and the Israeli forces, who tried to infiltrate Gaza from several positions, including the northern town of Beit Hanoun.
Al-Qassam Brigades, the military wing of Hamas, declared the resistance fighters had ambushed an Israeli unit in the southern town of Khan Yunis, as they detonated 5 explosive devices inflicting losses on the Israeli unit.
The enemy has also announced the injury of seven soldiers, with one seriously, after another Israeli unit was ambushed by resistance fighters, north of Beit Lahia, Al-Manar reported.
Meanwhile, the death toll of the Palestinians soared to 260 with the army bombarding Gaza by air and sea as well as from tanks massed along the border.
A 3-month-old baby was among the 19 Palestinians martyred on Friday.
Earlier, a Gaza-based human rights group said more than 80 percent of the Palestinian martyrs were civilians.
Also before the ground offensive was launched, Zionist Prime Minister Benjamin Netanyahu and his defense minister, Moshe Yaalon, instructed the army "to commence ground action to strike at the terrorist tunnels from the Gaza Strip into Israeli territory," the premier's office said.
For its part, Palestinian Islamic Resistance Movement, Hamas said the ground operation was destined to fail.
"What the occupier Israel failed to achieve through its air and sea raids, it will not be able to achieve with a ground offensive. It is bound to fail," Hamas chief Khaled Meshaal said.
A Hamas spokesman in Gaza said "Israel will pay a high price" for launching the ground operation and that the resistance movement "is ready for the confrontation".