GAZA CITY, Gaza Strip (AP) - Israeli bulldozers demolished more than a dozen tunnels Saturday in the Gaza Strip, and Palestinian authorities reported intensified airstrikes and shelling as the death toll from Israel's ground offensive rose to at least 342 Palestinians. Diplomats struggled to revive a cease-fire.
Israeli soldiers uncovered 34 shafts leading into about a dozen underground tunnels, some as deep as 30 meters (yards), that could be used to carry out attacks, the military said.
Still, Palestinian gunmen managed to infiltrate Israel from Gaza using another tunnel and killed two Israeli soldiers and injured several others, the military said. At least one Palestinian was killed in the clash. Hamas said 12 of its fighters participated in the attack.
It was the second time Palestinians had used their network of underground tunnels to penetrate Israel in the current round of fighting. Israel embarked on its ground offensive late Thursday in part to seek and destroy the tunnels.
Thirteen heavily armed Palestinians sneaked through a tunnel from Gaza and emerged inside Israel near a southern community. The militants were killed by an Israeli airstrike after they popped out of the tunnel.
Shimon Daniel, a retired brigadier general and former head of the Israeli military's engineer corps, said the military knew that Hamas had a large number of tunnels designed to assault Israel.
"I think finding 13 tunnels in such a short time is a great achievement," he told Channel 10 TV.
He said demolishing the tunnels is dangerous. Troops must assume the passages are booby trapped. Soldiers first close off the area and check for additional openings. Then robots go inside to look around, he said.
After that, the tunnels are destroyed either by special explosives or by heavy equipment. He said it can take up to 12 hours to destroy each tunnel.
"These tunnels aren't for hiding. They are intended for large attacks in Israeli communities and army bases," chief military spokesman Brig. Gen. Moti Almoz said.
Footage released by the Israeli military showed tunnels being demolished by army excavators and other equipment on the ground and by airstrikes from above.
Gaza Health Ministry spokesman Ashraf al-Kidra said the new round of airstrikes raised the death toll from the 12-day offensive to at least 342 Palestinians, many of them civilians.
In Israel, a Gaza rocket killed a man near the southern city of Dimona and wounded four people, police spokesman Micky Rosenfeld said, marking the second Israeli civilian casualty from the fighting. An Israeli soldier was killed after the start of the ground operation, probably from friendly fire.
Casualties could mount quickly if the military moves deeper into urban areas.
Some 50,000 Palestinians are already staying in United Nations shelters, according to UNRWA, the U.N. refugee agency for Palestinians.
Early Saturday, Israeli tank fire killed at least five members of the Al Zawaydi family at their home in Beit Lahiya, including two children. In a separate incident, tank shell fire killed three members of the Hamooda family in their home, among them two children.
In Gaza City, two boys and a 12-month-old infant neighbor were killed Friday evening following the break of the Ramadan fast. On Saturday, at least two of the bodies were carried by somber relatives during a funeral procession in Gaza City.
Israel says it is going to great lengths to avoid civilian casualties and blames them on Hamas, accusing it of firing from within residential neighborhoods and using civilians as "human shields."
The military said it has hit more than 2,350 targets in Gaza, including 1,100 rocket launchers, during the 12 days of fighting. It said that some 70 "terrorists" were and another 13 brought to Israel for questioning.
Gaza militants have fired more than 1,600 rockets at Israeli cities since July 8.
The military said also it had received intelligence reports that Palestinians had strapped explosives to animals and intended to send them toward soldiers. A donkey laden with explosives approached soldiers later on and blew up causing no injuries, it said.
An Egyptian truce proposal was rejected by Hamas, which has ruled Gaza since 2007 and has demanded the lifting of an Israeli and Egyptian blockade as part of any cease-fire agreement.
Israel's ground attack came after it became increasingly exasperated with rocket fire from Gaza, especially after Hamas rejected an Egyptian cease-fire plan earlier in the week.
Egyptian Foreign Minister Sameh Shukri on Saturday repeated a call for the two sides to adopt the cease-fire, saying it is the only offer on the table, despite efforts from Hamas backers Turkey and Qatar to broker a deal.
"This initiative still presents the chance for the two sides to cease fire, ending the bloodshed," he said. "It meets the needs of both sides. We will continue to propose it. We hope both sides accept it."
In a fresh effort to broker a truce, U.N. chief Ban Ki-moon was to leave Saturday for the Middle East to help mediate the Gaza conflict. A cease-fire is "indispensable" for urgently needed humanitarian efforts to succeed, the undersecretary-general for political affairs Jeffrey Feltman told an emergency meeting of the Security Council on Friday.
Israeli officials have said the offensive could last up to two weeks or possibly longer.
"The Palestinian people in the Gaza Strip will not surrender to the enemy and will not raise the white flag," Ziad Nakhala, a leader in the Islamic Jihad militant group, told a Palestinian radio station.
Hamas has survived Israeli offensives in the past, including a major three-week ground operation in January 2009 and another weeklong air offensive in 2012. It now controls an arsenal of thousands of rockets, including long-range projectiles, and has built a system of underground bunkers.
But Hamas is weaker than it was during the previous two offensives, with little international or even regional support from its main allies, Turkey and Qatar. Protests against the offensive took place Friday in Turkey, Jordan and the West Bank. Protests against Israel also continued in European countries.