Barak: War with Hamas 'to the bitter end'

Barak said the goal is to deal Hamas a "severe blow" and that the operation would be "widened and deepened as needed."

In Israel, 17 people have been killed in attacks from Gaza since the beginning of the year, including nine civilians — six of them killed by rockets — and eight soldiers, according to Israel's Foreign Ministry.

Israeli security officials have warned that the militants' range now includes Beersheba, a major city 30 miles (50 kilometers) from Gaza. Resident Mazal Ivgi, 62, said she had prepared a bomb shelter. "In the meantime we don't really believe it's going to happen, but when the first boom comes people will be worried," she said.

Israel began Saturday's assault by targeting Hamas security installations, and has broadened the attacks since then. On Sunday planes struck dozens of smuggling tunnels under the Gaza-Egypt border, cutting off a key lifeline that had supplied Hamas with weapons and Gaza with commercial goods.

In Jerusalem, Israel's Cabinet approved a call-up of 6,500 reserve soldiers Sunday in apparent preparation for a ground offensive. The final decision to call up reserves has yet to be made by the defense minister, and the Cabinet decision could be a pressure tactic. Military experts said Israel would need at least 10,000 soldiers for a full-scale invasion.