The Lebanese militant group Hezbollah says one of its commanders has been killed and is blaming neighboring Israel for his death.
The group said in a statement Wednesday that Hassan al-Laqis was killed as he returned to his home in southern Beirut around midnight. Security sources said he was shot while sitting in his car.
Hezbollah said Israel had tried to kill Laqis several times in the past and must bear "full responsibility" for his death.
Israeli foreign ministry spokesman Yigal Palmor denied Israel was involved, and a claim of responsibility was posted on Twitter in the name of a group calling itself the Ahrar al-Sunna Baalbek Brigade.
The claim, which could not be verified, denounced the arrests of Sunnis by Hezbollah in the Baalbek area of Lebanon.
There has been increased tension in Lebanon between Shi'ite Hezbollah and Sunni groups that oppose its role in the civil war in neighboring Syria, where it has sent fighters to support President Bashar al-Assad.
Armed clashes and bombings have spread into Lebanon, including deadly attacks in Beirut.
Some information in this report was contributed by Reuters.