Eleven Palestinian civilians were killed in an Israeli airstrike on a house in Gaza, according to Palestinian medics. Three women, six children, and a man are said to have been in the three-story building when it was attacked. Fighting in the region entered its fifth day Sunday as Israel mounted airstrikes in response to rocket attacks by Hamas militants. The 11 civilian fatalities are the most in any single incident so far. Rescue workers at the site were combing through the rubble for survivors.