Two Israeli civilians were killed in an explosion near an agricultural community in southern Israel on Tuesday, officials said, casting a pall over nationwide elections.
Islamic Jihad, a violent Palestinian militant group, claimed responsibility.
Israeli military officials said the explosion was caused either by a Palestinian rocket attack or stray ordnance along the border area with the Gaza Strip.
Medical officials said an adult and child apparently Arab shepherds were killed in the blast, which occurred near the border community of Nahal Oz.
In Gaza , Islamic Jihad said it had timed the attack to disrupt the Israeli election.
"We send a message to the Zionist entity that the blood of Palestinian people will not be at the expense of your elections," said Abu Abdullah, a spokesman for the group. Islamic Jihad's top rocket maker was killed in an explosion this month, though Israel denied involvement.
In past elections, Palestinian violence has driven voters toward hard-line parties, and Tuesday's attack could affect Tuesday's voting as well.
Hawkish parties have criticized front-runner Ehud Olmert's plan to withdraw unilaterally from much of the West Bank , saying it would invite Palestinian violence.
Olmert's opponents have pointed to the frequent rocket attacks that have continued out of Gaza since Israel withdrew from the area last summer.
The army said a total of four rockets were fired into Israel on Tuesday, reports the AP.
Europe has recognised the need for negotiations with Russia to discuss the security system on the continent. Russian Foreign Minister Sergei Lavrov is going to Macedonia for meetings with colleagues within the OSCE