With day two of its ground offensive in Gaza under way, Israel says it's discovered 13 tunnels used by Hamas to infiltrate the country or store weapons, reports AP. Israeli tanks and bulldozers are focusing on a strip about a mile wide near the border, looking for both tunnels and rocket pads, reports Reuters. Two Israeli soldiers were killed and two others injured today by Hamas fighters who emerged from one of those tunnels, reports the Washington Post. One Hamas militant also was killed in the firefight. Palestinians, meanwhile, say the death toll from Israeli airstrikes has passed 330, with nearly a quarter of those killed under the age of 18. In other developments: