Israeli military officials said on Sunday their aircraft had fired at two Palestinians trying to lay a bomb near the Gaza-Israel security fence.
A Palestinian ambulance driver said two bodies were found near Khuzaa in the southern Gaza Strip after the attack.
Residents said the two men, aged 18 and 20, were members of the Popular Resistance Committees, a group that has carried out several deadly bombings on Israeli targets in the past.
The resistance committees did not immediately comment on the incident.
The latest deaths bring the overall toll since the September 2000 start of the current Palestinian uprising to 4957, according to an AFP count. The majority have been Palestinian.
Also on Sunday, Palestinian officials said, Israeli soldiers killed two Palestinian teenagers who were throwing stones at soldiers during a military operation in a West Bank refugee camp.
The Israeli army said it was investigating the reports.
Witnesses said the shooting occurred in the Balata refugee - close to the northern West Bank city of Nablus - came after youths threw stones at army jeep.
Two soldiers got out of the vehicle and opened fire, killing two 17-year-old youths and wounding a third youth in the back, according to Palestinian medical officials.
Witnesses said the army entered Balata, a stronghold of Palestinian armed fighters, in search of fugitives. The army was still operating in the camp on Sunday afternoon, the witnesses said.
The two youngsters, identified as Ibrahim al-Sheikh Ali and Mohammed Natour, both of them aged 17, died after being hit in the neck by live bullets, medical sources said.
Earlier, another two stonethrowers were lightly injured when troops opened fire towards them with rubber bullets during a massive army operation which began before dawn, medical and security sources said.
A third man, said to be a civilian, was hit in the leg by live bullets and was being evacuated in an ambulance when troops moved in to arrest him, they added.