JERUSALEM (AP) -- The Israeli military launched what could be a long-term offensive against the Hamas-ruled Gaza Strip on Tuesday striking nearly 100 sites in Gaza and mobilizing troops for a possible ground invasion aimed at stopping a heavy barrage of rocket attacks against Israel.
The military said "Operation Protective Edge" looks to strike the Islamic Hamas group and end the rocket fire that has reached deeper into Israel and intensified in recent weeks.
The attacks come as tensions have soared over the killing of three Israeli teenagers and the apparent revenge killing of a Palestinian teenager by three Jewish suspects.
The military said it was seeking to "retrieve stability to the residents of southern Israel, eliminate Hamas' capabilities and destroy terror infrastructure operating against the State of Israel and its civilians."
Nearly 300 rockets and mortars have been fired at Israel in recent weeks, including a barrage of close to 100 projectiles on Monday alone, the military said, a huge surge after years of relative quiet that followed a previous Israeli campaign to root out Gaza rocket launchers.
Israel has responded with dozens of airstrikes, and eight Palestinian militants were killed Monday. Israel had signaled that it would not launch a larger offensive if the militant group Hamas ceased the rocket fire. But the same time Prime Minister Benjamin Netanyahu has instructed the military to prepare options for every scenario.
"We have repeatedly warned Hamas that this must stop and Israel's defense forces are currently acting to put an end of this once and for all," said Netanyahu spokesman Mark Regev.
Military spokesman Lt. Col. Peter Lerner said the current round of hostilities was being dictated by Hamas and Israel would continue its barrage so long as its citizens were under fire from Gaza.
"We don't expect it to be a short mission on our behalf," he said.
After a brief early morning lull, the rocket fire from Gaza resumed Tuesday with more than 15 rockets fired toward southern Israel, including the cities of Ashdod and Ashkelon. Associated Press video footage showed launches from inside Gaza residential neighborhoods.
The military said five of the projectiles were intercepted by the country's sophisticated Iron Dome missile defense system. A German cruise operator docking in the Ashdod port said debris fell onto one of its ships late Monday as it was departing.
None of the 2,700 vacationers and crew aboard the AIDAdiva was harmed and the ship continued to Crete without delay.
Israel's defense minister announced a special state of emergency in the region Tuesday as summer camps and kindergartens were shut down and residents were encouraged to stay close to their homes.
The military said it had targeted four houses belonging to Hamas militants involved in launching rockets at Israel or other militant activity. There were no reported casualties in the strikes.
