Three Hamas militants were killed and five wounded in an Israeli strike on the north of the Islamist-run Gaza
Strip, medics and the group said.
Hamas's armed wing, the Ezzedine Al-Qassam Brigades, said in a statement that all those killed in the attack around the town of Beit Lahiya were its members.
An Israeli army spokesman confirmed an air raid had been carried out in northern Gaza, targeting a group getting ready to launch mortars into Israeli territory.
Since the start of the year, militants in Gaza have launched some 2,000 projectiles toward Israeli territory, though not all of them landed inside the Jewish state, he said.
Wednesday's deaths bring to 5,963 the number of people who have been killed in Israeli-Palestinian violence since the start of the second Palestinian uprising in September 2000, the vast majority of them Palestinians.
Israeli military operation
More than two dozen Palestinians, nearly all of them militants, have died in Israeli raids in the overcrowded territory in less than two weeks, as the military widened the scope of its hits there.
Israeli Defence Minister Ehud Barak vowed on Tuesday to keep hitting militants in the territory, after authorising the army to target structures across Gaza, including manned Hamas positions, instead of focusing only on rocket-launching cells and infrastructure as it had previously.
Mr Barak also warned that the military would eventually launch a widescale offensive inside Gaza with the aim of halting the daily firing of rockets and mortars from the territory into Israel.
Prime Minister Ehud Olmert has been under increasing pressure to launch a vast military operation inside the coastal strip, but said in an interview last week that he would take his time in deciding how to deal with the territory.
Hamas, the Islamic Resistance Movement that is pledged to Israel's destruction, seized control of Gaza in mid-June after routing forces loyal to moderate Palestinian president Mahmoud Abbas.
Since then, Israel has sought to further isolate the Islamists, tightening restrictions on the movement of goods and people in and out of the impoverished territory.