An Israeli army spokesman confirmed two air strikes and ground shelling on the northern Gaza Strip.
"An armed rocket launcher was targeted with two militants standing beside it ready to launch rockets in northern Gaza Strip," the army spokesman said.
Also targeted was a group of Palestinians responsible for firing three rockets that exploded in southern Israel early on Sunday - no casualties or damage was reported.
The latest deaths bring the number of people killed since the outbreak of the Palestinian uprising in 2000 to 5,921 - the vast majority of which has been Palestinians, according to an AFP tally.
Ehud Barak, the Israeli defence minister, warned last week that every day brought closer the prospect of a full-scale military operation in the Gaza Strip, where more limited raids have been unable to counter rocket fire.
Since Hamas took power more than 1,000 rockets and mortar rounds have hit southern Israel, rarely causing casualties but creating a climate of fear.
Israel's attorney-general has suspended a government decision to reduce badly needed electricity supplies to the impoverished Strip in a bid to put pressure on Palestinian fighters.