The Palestinian death toll from Israeli air strikes rose to 162. <br /> <br />JERUSALEM (AFP) - Israeli navy commandos launched a ground operation overnight in the north of the Gaza Strip, the first since the offensive against Hamas began, Israeli public radio said early Sunday. <br />Hamas confirmed that Israeli commandos had exchanged gunfire with some Palestinian fighters. A military spokesman later said four Israeli soldiers had been lightly wounded during the operation. <br />It was the first ground operation in Gaza by the Israeli military since the start of its offensive on Tuesday. <br />Meanwhile, the toll from Israeli air strikes rose to 162. Saturday was the bloodiest day since the conflict erupted on Tuesday, claiming 56 Palestinian lives including a two-year-old child and a 73-year-old woman. <br />Israel continued to build up troops along the Gaza border ahead of a possible ground invasion, warning Palestinians in northern Gaza to evacuate their homes. <br />With the rising Palestinian death toll, and with no Israelis killed, the UN Security Council unanimously urged to respect "international humanitarian laws" and stop the loss of life.