Troops target Hamas tunnels after airstrikes prove ineffective

Israeli troops pushed deeper into Gaza on Friday to destroy rocket-launching sites and tunnels, firing volleys of tank shells and clashing with Palestinian fighters in a high-stakes ground offensive meant to weaken the enclave's Hamas rulers.

Israel launched the operation late on Thursday, following a 10-day campaign of more than 2,000 airstrikes against Gaza that had failed to halt Hamas rocket fire on Israeli cities.

Israel's first major ground offensive in Gaza in just over five years came as Egyptian cease-fire efforts stalled. Israel has accepted Cairo's offer to halt hostilities, but Hamas refused, demanding that Israel and Egypt first give guarantees to ease the blockade on Gaza.

Throughout the night, the thud of tank shells echoed across Gaza, often just a few seconds apart. Several explosions from Israeli missile strikes shook high-rise buildings in central Gaza.

At Gaza's main Shifa Hospital, casualties quickly began arriving, including several members of the same family wounded by shrapnel from tank shells. Among those hurt were a toddler and a boy of elementary school age, their bodies pocked by small bloody wounds.

Gaza health officials said 19 Palestinians have been killed since the ground operation began. The Israeli military said it killed 14 militants in different exchanges of fire.

The Israeli military said one soldier was killed in Gaza Strip, the first Israeli casualty among troops. The circumstances behind his death were not immediately clear, with Hamas' military wing saying it ambushed Israeli units in the northern town of Beit Lahiya but Israeli media saying it was likely a case of friendly fire.

Israel's chief military spokesman Moti Almoz told Army Radio "there were a number of points of friction through the night" and said the military was investigating the circumstances behind the soldier's death.

Israeli officials have said the goal is to weaken Hamas militarily and have not addressed the possibility of driving the Islamic militants from power.

However, Hamas has survived Israeli offensives in the past, including a major ground operation in 2009 from which it emerged militarily weaker, but then recovered. Hamas has since assembled thousands of rockets and built a system of underground bunkers.

Israel had been reticent about launching a ground offensive for fear of endangering its own soldiers and drawing international condemnation over Palestinian civilian deaths.

Since the July 8 start of the air campaign, 260 Palestinians have been killed - including 14 children under the age of 12 on Wednesday and Thursday - and more than 2,000 wounded, Palestinian health officials said. In Israel, one civilian died, and several were wounded.

Israeli public opinion appears to strongly support the offensive after days of unrelenting rocket fire from Gaza and years of southern Israeli residents living under the threat. Gaza militants have fired more than 1,500 rockets at Israel over the past 11 days.