Capping a flurry of renewed violence in the Gaza Strip, Israeli jets Friday struck three Palestinian targets, including a deserted building and a tunnel that Israel says militants used to smuggle in weapons.
At least six Palestinians, including two women and a child, were injured in the attacks, Palestinian hospital officials said.
According to Israeli military officials, the airstrikes were in retaliation for some of the heaviest concentration of rocket and mortar fire from Gaza militants in months.
Israeli officials said they would hold Hamas, the armed Palestinian group that controls Gaza, responsible for the rockets.
But another group, Popular Resistance Committees, claimed responsibility for the recent mortar fire, saying it was retaliating for last week's assassinations by Israel of two senior members of the Al Qaeda-inspired Army of Islam and an earlier Israeli strike that killed a third leader.
Abu Ataya, a spokesman for the committees, said the group would not "stand silent" in light of "the return of the Zionist enemy to the policy of cowardly assassinations, most recently the assassination of three of the mujahedin from the Army of Islam."
Israel officials said the men they killed had been plotting terrorist attacks against Israeli civilians vacationing in the Sinai peninsula.
A senior intelligence officer in Israel alleged recently that Hamas has been secretly working with the Army of Islam to plan attacks in the Sinai and other terrorist strikes, but has tried to hide its participation to avoid being attacked by Israel or criticized by the international community.
"They're using proxies so they won't be blamed," the official said.
Last week, Israel urged its citizens to leave Sinai, warning of a kidnapping threat.
Israeli officials said the recent rocket and mortar fire involved 10 projectiles, including one Grad rocket, fired from Gaza during a 24-hour period. Most landed in open space in southern Israel, but one damaged a farm, injuring cows and destroying a shed, according to local media reports.
The violence comes as the Israeli government is preparing to vote on whether to renew restrictions on settlement construction in the West Bank in order to revive U.S.-sponsored peace talks.
Special correspondent Rushdi abu Alouf in Gaza City contributed to this report.