An Israeli strike about 60 km inside Lebanon's southern border on Saturday targeted a Palestinian figure close to Hamas but he survived, four security sources said.
Three other people were killed, including one member of the powerful, Iran-backed Lebanese armed group Hezbollah, a Hamas ally, the security sources also told Reuters.
One source said the person targeted was close to Saleh al-Arouri, the Hamas deputy chief killed last month in a suspected Israeli strike on a suburb of Beirut.
Saturday's strike was much deeper into Lebanese territory than the usual exchanges of fire between Hezbollah and Israel's military, which have been mostly limited to the border region.
There was no immediate comment from Hamas in Lebanon or from the Israeli military.
Reporting by Maya Gebeily and Laila Bassam