Israeli tanks and guns have kept up their assault on Gaza throughout the night, warning the operation will be neither easy nor short-lived. Thousands of troops moved into the enclave to attack Hamas rocket positions and to overthrow what commanders called the terrorist infrastructure.There have been casualties on both sides: Israel claimed at least eight Palestinian fighters were killed, but admitted 30 of its own soldiers were wounded – two of them seriously. They were evacuated back into Israel for treatment. Much of Gaza City was plunged into darkness, with explosions seen throughout the crowded area. Palestinian medical services were at full stretch, the United Nations predicted a catastrophe. Israel attacked on three fronts: the main strike came from the northeast, a smaller force entered Gaza along the coast with a third column further south.