Palestinian militants have fired more rockets from Gaza into Israel, days after Israeli Prime Minister Ehud Olmert threatened to respond to the attacks.
According to Israel Defense Forces, Hamas fired at least nine rockets and nine mortars against Israeli territory.
Israel has responded by calling off a re-opening of border crossings it had planned for this Wednesday to allow limited supplies into Gaza from Egypt.
Violence escalated last Friday, when the Hamas militants said they would not renew an uneasy six-month truce, citing Israeli blockades. Palestinian rockets fired from Gaza last week prompted Israeli air strikes.
Defense Minister Ehud Barak said he has already ordered the army to create plans to respond to the attacks.