The armed wing of Gaza's ruling Hamas movement on Tuesday said it fired 10 rockets at Israel in a rare show of force after three Israeli air strikes killed six Palestinians.
The claim came shortly after Israel on Tuesday afternoon staged another air strike over Deir al-Balah in central Gaza, injuring two men on a motorcycle, one of them critically, medical officials said.
Such fire by the Ezzedine al-Qassam Brigades, which generally maintains a tacit truce with Israel, is very rare.
"This is our answer to the Zionist crimes. It will continue if they carry out more strikes on Gaza," a statement said.
Israel's military confirmed 11 rockets had hit the country's south since midnight. Another three rockets had been fired on Monday.
A military spokesman also confirmed there was "a targeted strike" on Deir al-Balah aimed at militants "responsible for the rockets fired at Israel over the past few hours."
Army figures show that since the start of 2012, Gaza militants have fired more than 290 rockets into Israel.
Earlier Tuesday, medics recovered the bodies of two Palestinian teenagers after an early morning air strike, also in Deir al-Balah.
This raised to six the number of Palestinians killed in a series of Israeli strikes since Monday, all carried out just hours after a deadly ambush along Israel's southern border with Egypt.
At its weekly meeting, the Palestinian cabinet condemned what it called the "continuous Israeli escalation" and called for "international protection to the Palestinian people," according to a statement.
Israel has said the sudden spike -- three deadly air raids in just over 12 hours -- was "in no way related" to the border incident, with the military saying the air force targeted militants planning or engaged in attacks on the Jewish state.
The overnight strike which killed two 17-year-old youths took place shortly after midnight but their bodies were only recovered after dawn "when an ambulance could get to the scene," medics told AFP.
Hospital staff named the pair as Mohammed Bassem Abu Mealiq and Yusef al-Talbani. Witnesses said they had been trying to breach the fence bordering Israel when they were hit.
The military said it had targeted "a terrorist squad handling an explosive device" near the security fence in central Gaza.
On Monday, four Palestinians were killed in two Israeli sorties over Beit Hanun in northern Gaza that also wounded three other people, medics said.
One of those killed was identified by the Qassam Brigades as one of its militants: 23-year-old Jihad Abu Shbab. The second victim, Mohammed al-Zaanin, 25, was not affiliated with any armed faction.
Israel said it had targeted "a terrorist squad attempting to fire a rocket at Israel."
The military said they were part of a "squad of snipers operating near the security fence in the northern Gaza Strip" that had fired at an Israeli farmer working near the fence last Thursday.
The last major flare-up in Gaza was in March when four days of tit-for-tat violence left 26 Palestinians dead, and saw militants firing more than 200 rockets into Israel.
The fighting erupted when Israel assassinated a militant leader from the Popular Resistance Committees whom it said was responsible for planning an attack along Israel's southern border with Egypt in August 2011 in which gunmen sneaked over the frontier and killed eight Israelis.
Within hours, Israel hit back at Gaza, sparking eight days of bloodshed that left 26 Palestinians and an Israeli dead.
Monday's border attack raised fears Israel would once again hold Gaza militants responsible, although there was no such claim in the immediate aftermath of the incident in which an Israeli civilian and two gunmen died.
Asked about the possible involvement of groups from Gaza, Israeli military spokeswoman Avital Leibovich said: "There is speculation about that. Intelligence is checking right now."
Source: AFP Global Edition