Hamas radio identified the dead man as Mubarak al-Hassanat, a senior official in the Hamas-controlled Interior Ministry. The ministry oversees all Hamas security forces in the Gaza Strip.
Al-Hassanat, 37, also was a top member of the Popular Resistance Committees, a Hamas-linked group that frequently fires rockets into Israel.
The Israeli army confirmed the airstrike, saying the car was carrying a senior operative responsible for rocket and mortar attacks on Israel. Palestinian militants in Gaza fire rockets and mortars almost daily.