Ahmed Jabari, head of Hamas' military wing, was killed Wednesday in a targeted strike by Israeli forces in the Gaza Strip.
The Palestinian Islamist group said an Israeli airstrike hit a car in the Gaza Strip, killing both Jabari, who ran the organization's armed wing, the Izz el-Deen Al-Qassam, and a passenger.
Israel's Shin Bet domestic intelligence service confirmed it had carried out the attack, saying it had killed Jabari because of his "decade-long terrorist activity."
IDF Spokesperson said the purpose of the strikes was to deal a heavy blow to the Hamas command and control apparatus and to the organization's terrorist infrastructure.
The incident appeared to end a 24-hour lull in cross-border violence that surged this week.
Jabari is the most senior Hamas official to be killed since Operation Cast Lead in Gaza four years ago. He has long topped Israel's most-wanted list.
Jabari, a relative of one of the founders of Hamas, Dr. Abdel Aziz Rantisi, was responsible for the attack on Kerem Shalom, when IDF soldier Gilad Shalit was kidnapped and two other soldiers killed. Jabari was in charge of negotiations during Shalit's five years in captivity.
On Tuesday, Prime Minister Benjamin Netanyahu told mayors of southern Israeli cities under rocket attack that it was his responsibility to choose the right time to "exact the heaviest price" for the continual rocket fire from Gaza.
Since the flare-up with Gaza began, Netanyahu and Defense Minister Ehud Barak have promised a sharp Israeli response to the rocket fire.
During the Be'er Sheva meeting with the southern Israeli mayors, Netanyahu said that Israel is not expected to undertake significant military action in Gaza at this stage, or to renew assassinations of Gaza militants.
"I am responsible for us choosing the right time to exact the heaviest price, and so be it," Netanyahu said. "Whoever thinks that they can damage the daily lives of residents of the south, and that they won't pay a heavy price for this – they are mistaken."