Saturday's massive Israeli airstikes came in mid-morning, when official buildings and security compounds were filled with personnel and children were at school, and not, as many had anticipated, at night. Expecting some kind of Israeli response, the Hamas leaders in Gaza had already been in hiding for two days. The air strikes started suddenly and caused widespread panic and confusion in Gaza, as black clouds of smoke rose above the territory, ruled by Hamas for the past 18 months. Some of the Israeli missiles struck in densely populated areas as children were leaving school, and women rushed into the streets frantically looking for their children. It wasn't immediately clear how many civilian casualties there were. Said Masri sat in the middle of a Gaza City street, close to a security compound, alternately slapping his face and covering his head with dust from the bombed-out building. “My son is gone, my son is gone,” wailed Masri, 57. The shopkeeper said he sent his 9-year-old son out to purchase cigarettes minutes before the airstrikes began and now could not find him. “May I burn like the cigarettes, may Israel burn,” Masri moaned. Israel told its civilians near Gaza to take cover as militants began retaliating with rockets. “We had warned the civilian population in the Gaza Strip of our attacks and Hamas, which hides within this population, is solely responsible for this situation,” an Israeli army spokesman said. He said Israeli warplanes had carried out the strikes “to stop the terrorist attacks of the past several weeks against Israeli civilian installations.” At Shifa Hospital in Gaza City, scores of dead bodies were laid out in front of the morgue waiting for family members to identify them. Many were dismembered. Inside the hospital, relatives carried a five-month old baby who had suffered a serious head wound from shrapnel. Overwhelmed, the hospital staff seemed unable to offer help. At the Gaza City police station, at least 15 traffic police who had been training in a courtyard were killed on the spot. Tamer Kahrouf, 24, a civilian who had been working on a construction site in Jabaliya, north of Gaza City, said he saw his two brothers and uncle killed before his eyes when the Israeli planes bombed a security post nearby. Mr. Kharouf was wounded and bleeding from the head. Women were wailing as they searched for their relatives among the dead. Sawsan Al-Ajab, 50, was looking for two sons, aged 32 and 24, who both worked at the Gaza police station.