One was killed in an Israeli air strike near the town of Khan Yunus, while a second was killed in a separate incident nearby, witnesses said.
They said both were civilians, but the Israeli army said the first was with another armed man close to the border with Israel when he was hit and the second was shot on suspicion of planting explosives.
Residents said Israeli troops had detained 10 people near Khan Yunus. It was unclear if they were fighters.
An Israeli military source said a force was in the area as part of ongoing operations there, and that some people in the village had been detained.
Four Palestinians had been killed earlier in two night-time airstrikes on cars in the Rafah refugee camp in Gaza.
Helicopter gunships fired on a vehicle carrying two members of the Izz al-Din al-Qassam Brigades. The bridage is the armed wing of the ruling Hamas faction.
|Palestinians inspect the wreckage
of one of the cars hit in Rafah
The men were killed and residents said the blast caused a huge fire. Dozens of bystanders were hurt.
One witness, Salim Abu Jazer, said the initial blast was followed by two smaller explosions in the car.
An Israeli military spokeswoman said the secondary explosions indicated that there were explosives in the car.
Two people were later killed in a separate car explosion nearby, also an apparent airstrike, but the Israeli military made no immediate comment.