Northern Gaza was invaded Thursday by Israeli artillery, tanks and other ground elements. The invasion followed ten days of combat by aerial bombardment, during which the Hamas government of Gaza lobbed rockets into Israel while Gaza was also struck with rockets and missiles from Israeli land-based sites, as well as from fighter jets.
Netanyahu said he ordered the military to "prepare for the possibility of widening, significantly" the ground operation in Gaza.
The Israeli government said the campaign was to uncover and destroy tunnels under the Gaza-Israel border, used by Hamas forces to enter Israel. Eight "tunnel access points" were discovered in the first hours of the incursion, the Israeli military said, and over 150 sites were hit by artillery or rocket fire.
"We chose to go to this operation after we exhausted the other options and with the understanding that without this operation the price we pay will be much higher," Netanyahu said in a televised address prior to the launch of the ground attack, noting that Israel would "act systematically and with power against a murderous terror organization and its partners."
At least 20 Palestinians in Gaza have been killed since the ground attack began, and one Israeli soldier was killed, possibly, Israeli news media suggested, accidentally by friendly fire.
Electricity in Gaza, obtained from Israel, was cut because of downed electrical lines. Social media revealed street battles in Gaza City and the evacuation of towns across the region. Gaza City streets were largely deserted, although its hospitals remained busy with casualties.
The large number of Palestinian casualties is a cause of controversy in the conflict, with deaths and injuries on the Palestinian side significantly higher than that of Israel. Estimates by the United Nations indicate the majority of Palestinians killed were civilians, not soldiers, and over 50 of the approximately 260 killed were children.
After U.N. Secretary-General Ban Ki-moon called on Israel to "do more" to prevent civilian casualties, Netanyahu said Friday Israel has "a moral army like no other," and "does not aspire to hurt even one innocent person, not even one." He added Hamas and other militant groups use "their citizens as human shields."
Hamas has been accused of hiding weapons and other war material in schools, hospitals and mosques to reduce the chance of their loss by bombardment.