Islamic Jihad said all the five victims were its members.
Another two Israeli air attacks in the nearby town of Deir al-Balah killed a sixth person and wounded five people, local Palestinian hospital officials said.
"There were three aerial attacks ... two of them were against vehicles carrying terror operatives and one of them was against terror operatives without a vehicle," an Israeli army spokeswoman said.
One of those killed in Tuesday's Israeli raids was Moataz Doghmush, a senior fighter in the Army of Islam, an armed faction believed to be linked to al-Qaeda, Hassanein said.
In response, Palestinian fighters fired seven rockets into Israel, the Israeli military said.
The exchange of fire came hours before Cairo announced that Israel and Hamas had agreed to an Egyptian-mediated ceasefire agreement to take effect on Thursday.
At least 515 people have been killed since Israel and the Palestinians relaunched peace negotiations at a conference in the US city of Annapolis in November, most of them Palestinian fighters, according to an AFP count.