Palestinians carry the bodies of three toddlers Ahmed, Mohamed, and Issa Samouni, who according to... 
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Israeli shells slammed into Gaza and ground forces edged closer to major population centers Tuesday, taking more civilian lives after Israel ignored mounting international calls for an immediate cease-fire.
In fighting that raged early Tuesday morning, at least 18 people were killed in shelling up and down the Gaza Strip from tanks and naval craft, local hospital officials said. Only two of the dead were confirmed as militants.
Tanks rumbled closer to the towns of Khan Younis and Dir el Balah in south and central Gaza but were still several kilometers (miles) outside, witnesses said, adding that the sounds of fighting could be heard from around the new Israeli positions. Israel already has encircled Gaza City, the area's biggest city.
Israel launched its offensive on Dec. 27 in a bid to halt repeated Palestinian rocket attacks on its southern towns. After a weeklong air campaign, Israeli ground forces invaded Gaza over the weekend. More than 500 Palestinians have been killed, including more than 100 civilians, according to United Nations figures. Nine Israelis have died since the operation began.
The rising civilian death toll has drawn international condemnations and raised concerns of a looming humanitarian disaster. Many Gazans are without electricity or running water, thousands have been displaced from their homes and residents say that without distribution disrupted, food supplies are running thin.
In one incident overnight, three people were killed when Israel attacked a U.N. school where hundreds had taken shelter.
"There's nowhere safe in Gaza. Everyone here is terrorized and traumatized," said John Ging, the top U.N. official in Gaza, blaming the international community for allowing the violence to continue.
"I am appealing to political leaders here and in the region and the world to get their act together and stop this," he said, speaking at Gaza's largest hospital. "They are responsible for these deaths."
Israel says it won't stop the assault until its southern towns are freed of the threat of Palestinian rocket fire and it receives international guarantees that Hamas, a militant group backed by Iran and Syria, will not restock its weapons stockpile. It blames Hamas for the civilian casualties, saying the group intentionally seeks cover in crowded residential areas.
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