At least 170 killed in Israeli attacks on Gaza * Story Highlights * NEW: Death toll in raids climbs to 170; Palestinians say 110 hospitalized * White House urges Hamas to stop attacks, Israel to avoid hitting civilians * One Israeli killed in rocket attack reported by Hamas military wing, sources say * Many senior Hamas police officials, including chief, reportedly killed GAZA CITY (CNN) -- Israeli airstrikes pounded targets in Gaza on Saturday, killing at least 170 people, Palestinian medical sources said. An Israeli army spokeswoman said her country is ready to continue the attacks "as long as it takes." Palestinian medical sources said 110 people were hospitalized in Gaza in serious to critical condition. Earlier Saturday, the sources said at least 250 people had been wounded in the raids. The militant group Hamas, which controls the government in Gaza, vowed to retaliate. The strikes followed several days of rocket attacks from Gaza into Israel. Hamas police stations were hit, killing many senior police commanders, a reporter in Gaza said. Maj. Gen. Tawfeeq Al-Jaber, a senior commander in the Hamas police force, was killed, as was Ismail Jabari, who headed the special police force in Gaza, Palestinian sources said. Israeli Maj. Avital Leibovich told CNN the military began the attacks "in order to preserve the security situation in Israel." "We are prepared for any type of scenario right now. We have our own operation and assessments as we go along, and we are ready to continue this operation as long as it takes," Leibovich said by phone from Tel Aviv. VideoWatch panicked Palestinians try to help the wounded Â» Not long after Hamas called for retribution, an Israeli woman was killed when a rocket fired from Gaza hit a house in Netivot, about six miles east of Gaza, Israeli police spokesman Mickey Rosenfeld said. Hamas acknowledged firing the rocket. Map Â» Two other Israelis were listed in "medium to serious" condition at a hospital in Bersheba, Rosenfeld said. Rosenfeld said at least 15 missiles from Gaza had landed in Israel by late afternoon. The Israeli Defense Ministry issued a statement saying Prime Minister Ehud Olmert ordered the military into action based on a decision by the Cabinet. "The action will continue and will widen as much as is demanded according to the evaluation of the situation by the high command of the army," the statement said. Palestinian legislator Hanan Ashrawi, speaking from Ramallah in the West Bank, accused Israel of ignoring the terms of the tenuous six-month cease-fire that expired a week ago. "This is certainly a very cruel escalation, a relentless bombardment of a captive civilian population that has already been under siege for months, that has been deprived of basic requirements like food and medicines and fuel and power," she said. VideoWatch Ashrawi condemn the airstrikes Â» The Arab League scheduled an emergency meeting in Cairo, Egypt, at 7 p.m. (noon ET) Sunday to discuss the outbreak of violence. White House spokesman Gordon Johndroe called on Hamas to cease its rocket attacks on Israel and urged Israel "to avoid civilian casualties as it targets Hamas in Gaza." A statement from the Israel Defense Forces (IDF) said Israeli aircraft attacked "a series of Hamas targets and infrastructure facilities." "The Air Force activity came as a result of the continuation of terror activity by Hamas terror organization from the Gaza Strip, and the duration of rocket launching and targeting Israeli civilians," the IDF statement said. Video showed severely wounded people being loaded into cars and driven to hospitals. Inside one Gaza hospital, doctors appeared overwhelmed; the floors were covered with wounded men and some children. "Many killed and many injured," a Gaza-based reporter said. "People are running in the streets." The Egyptian government sent 20 ambulances, along with medical personnel, to Rafah at its border with Gaza to help with the wounded, an Egyptian official said. The reporter, who is not being named for safety reasons, said the attacks were the biggest he had seen in his decades in Gaza. The IDF said the targets "include Hamas terror operatives that operated from the organization's headquarters, training camps and weaponry storage warehouses." The shaky six-month truce between the Hamas government in Gaza and Israel expired a week ago. Under the Egyptian-brokered deal, Hamas agreed to end militant attacks on Israel from Gaza, and Israel agreed to halt raids inside the territory and ease its blockade on humanitarian goods. Israel on Friday opened three border crossings for the first time in 10 days to allow food, medical supplies and other humanitarian goods into Gaza, but Palestinian rocket attacks continued.