Crowds of mourners have turned out in the Lebanese town of Baalbek for the funeral of a Hizbollah commander shot in the head at close range outside his home on Wednesday.
The organisation has blamed Israel for the death of Hassan al Lakkis but Israel denies the accusation. Instead, it suggests the killing was the work of Sunnis taking revenge for Hizbollah's involvement in Syria.
Two previously unheard-of groups say they carried out the attack but a BBC correspondent in Beirut says their involvement is unconfirmed, and the identity of the attackers remains a mystery, for the time being at least.
Little is known publicly about Mr Lakkis, but he was reputedly close to Hizbollah leader Hassan Nasrallah and an expert in weapons manufacturing.
Hizbollah says he was killed as he returned home at about midnight, a day after Mr Nasrallah said Saudi Arabia was behind last month's bombings outside the Iranian embassy in Beirut.
Iran is a major backer of Hizbollah, which has sent fighters to Syria to back the government of President Bashar al-Assad.
Mr Assad comes from the Alawite sect, a heterodox offshoot of Shia Islam. Saudi Arabia is Sunni Muslim and has been supporting some of the rebels in Syria.