Israel ready to 'significantly expand' Gaza operation. (VIDEO)

Israeli bombs are hitting refugee camps in Gaza, killing four children, as Israel claims it's ready to 'significantly expand' the assault. In all, the death toll in the bombardment has risen to at least 50 Palestinians since Wednesday. Hamas has been retaliating against the attacks with rocket fire, killing three Israelis over the same period. Its most recent strikes hit the south of Israel and also targeted Tel Aviv.