Israel must be ready for a "lengthy" military campaign in the Gaza Strip, Prime Minister Benjamin Netanyahu said on Monday.
"We must be prepared for a lengthy campaign" in Gaza, he said in a speech televised shortly after at least four people were killed in southern Israel by a mortar fired by fighters in Gaza.
"Israeli citizens cannot live with the threat from rockets and from death tunnels -- death from above and from below," he said.
"We will not end this operation without neutralising the tunnels whose sole purpose is killing our citizens."
Israel has killed more than 1,050 Palestinians since it started its war on Gaza three weeks ago.
50 Israelis have been killed.
*This story was edited by Ahram Online