Israel's army claimed the air strike was aimed at a group of Palestinians preparing to fire rockets into Israel.
Lebanese security sources, however, said the air strike came after three rockets were fired at Israel by a group of Palestinians enraged by Monday's assassination of Shaikh Ahmad Yasin in Gaza.
A third Palestinian was wounded in the air strike. The security sources failed to say whether the Palestinians belonged to a particular group.
In the Gaza Strip, Hamas sources said two of its men were killed near the Jewish settlement of Morag by Israeli occupation troops while planting a bomb.
Lebanon's Hizb Allah fighters, meanwhile, attacked Israeli posts along a disputed border on Monday, in response to the assassination of Shaikh Yasin.
Hizb Allah leader Shaikh Hasan Nasr Allah said after Shaikh Yasin's death that: "The Zionists will discover soon that they have committed a very big folly to add to their series of previous follies."