The Qassam brigades, the military wing of Hamas, announced that they were no longer committed to its de facto ceasefire with Israel in effect since more than two years ago.
"There is no longer any truce with the enemy," said the statement broadcast over a Hamas radio station early on Saturday.
Rockets have been launched from Gaza into Israel and Israeli aircraft have struck targets in the Palestinian territory in the back-and-forth aftermath of deadly attacks a day before in southern Israel.
At least eleven Palestinians have been killed and 30 were injured in the past 24 hours by Israeli air strikes on the Gaza Strip which began on Thursday. Four Israelis have been injured by rockets fired from Gaza.
The casualties are a result of exchanged attacks following a series of deadly assaults by gunmen who targeted two buses, a car and an army vehicle in the area north of Israel’s Red Sea resort of Eilat on Thursday.
Eight Israelis, including six civilians and two soldiers, were killed that day alongside seven of the attackers, among which were two suicide bombers who detonated near a bus and during a confrontation with soldiers. Over 40 Israelis were also wounded, local media reported.
Israel said the attackers had infiltrated from the Hamas-run Gaza Strip and vowed, and officials vowed to "hunt down" the perpetrators.
Israeli officials have blamed a Gaza-based militant group called the Popular Resistance Committees (PRC) for Thursday’s attacks, although the faction has denied any involvement. The PRC is not affiliated with the Hamas movement that governs Gaza.
Three Palestinians including a 5-year-old boy were killed and 3 passersby were injured in an attack on a vehicle in central Gazas City. Al Jazeera’s Safwat Al Kahlout reported.
Previously, the latest air strike on the Gaza Strip hit Bureij refugee camp in central Gaza late Friday night, killing two men.
The Al-Quds Brigade, the armed wing of the militant Islamic Jihad, confirmed that one of the men, Emad Abu Abda, was their member. The other man’s identity and possible affiliations were not immediately known.
This was the Israeli air forces’ sixth operation since beginning their raids in retaliation for Thursday’s incidents.
Hours earlier, the Israeli air force targeted rocket launchers, "two weapons manufacturing sites in central Gaza" and "terrorist activity in the north and the south" of the strip", the Israeli military told Al Jazeera.
Five members of the PRC, including its leader, were killed in Thursday’s overnight air strike in Gaza’s southern city of Rafah and another killed on Friday, Al Kahlout reported from Gaza.
Abu Mujahid, a PRC spokesman, has said the group vows to take revenge "against everything and everyone" for its members’ deaths.
Medical sources said at least three civilians have also been killed, including two boys aged three and 13 who died early on Friday.
Rockets from Gaza
Over 24 rockets had been fired from Gaza into Israel by Friday night, some reaching as far as the southern coastal city of Ashdod, the Israeli military confirmed.
Two rockets fired at Ashdod "caused damage and injuries at a synagogue and school", according to a military statement. Four Israeli civilians were injured in Ashdod, the Israeli medical service Magen David Adom told Al Jazeera.
Binyamin Netanyahu, the Israeli prime minister, said on Thursday that his country "will exact a price, a very heavy price" for those who "attempt to escalate terrorist war against Israel" and "believe that they can attack our citizens and get away with it".
While visiting the wounded at a medical center in the southern city of Beer Sheva on Friday, Netanyahu said Israel’s ongoing retaliatory measures against Gaza is not Israel’s "first reaction". He also pledged to "speed up" the construction of a bolstered barrier along its southern border with Egypt to cover 100km of the stretch by the end of the year.
The barrier currently runs for 45km of the full 200km stretch. The Israeli defence ministry had planned several months ago to complete the project by 2012.
Lieutenant Colonel Avital Leibovich, a spokeswoman for the Israeli military, said Israel does not seek to escalate the situation because it is "not the ones who chose to target civilian buses and vehicles".
Leibovich said Israeli forces were targeting "not only specific terror organisations in Gaza, but rather anyone who has some influence … with terror", including groups of people it suspects of launching rocket attacks.
According to Gaza residents, three Hamas-controlled compounds in Rafah were among the targets hit in Thursday’s late night air strikes.
Ghazi Hamad, Hamas’ deputy foreign minister, denied any connection between Hamas or the people of Gaza with the attacks in southern Israel.
"From the first moment we are surprised that Israel started to target people. To target civilians, to target places, to target buildings before knowing who stands behind this operation. So, I think that Israel [always] considers Gaza a weak point that they can target them under any circumstances," he said.
Hamad called the rocket attacks from Gaza,"a kind of natural reaction against the Israeli aggression against our people."
He continued: "If they stop their aggression and attacks against Gaza, I think people here are interested in keeping Gaza calm and quiet."
Hamad also said that Hamas was "surprised" that members of the international community had not condemned Israel for "killing civilians".
(Al Jazeera and Agencies)