But a prominent Shiite cleric and senior Hezbollah official, Sheik Mohammed Yazbek, has publicly accused rival groups of Sunni jihadists of shooting to death Hassan al-Laqqis outside his suburban apartment block.
Yazbek's unequivocal accusation is widely seen as a more accurate assessment of the assassination, and what may be coming next in the Middle East's current killing frenzy.
A previously unknown group, the Brigades of the Free Sunnis in Baalbek, capital of the Bekaa Valley, Hezbollah's heartland, had claimed responsibility for assassinating al-Laqqis.
Hezbollah pointed to the Israelis, who have systematically assassinated Hezbollah leaders since they killed Sheik Ragheb Harb, one of the group's founding fathers, in South Lebanon Feb. 16, 1984.
The feeling is that Hezbollah, with thousands of fighters deployed in Syria aiding the threatened regime of President Bashar Assad, did not want to find itself dragged into a sectarian fight in its own backyard that would seriously weaken the Damascus regime.
But either way, whether it was Israel or Sunni militants who killed al-Laqqis as part of campaign of escalating attacks on Hezbollah and its Iran patron, the outlook is grim.
It was unclear why Yazbek focused on the Sunni threat when he spoke at al-Laqqis' funeral in Baalbek, the slain man's hometown, attended by top Hezbollah leaders and thousands of mourners who turned out in freezing winter rain.
But he insisted those responsible for the assassination were behind attacks on Hezbollah strongholds in the last four months.
These included a car bombing in south Beirut Aug. 15 that killed 27 people and wounded 300, mostly Shiite civilians.
The Iranian embassy, inside Hezbollah's south Beirut bastion, was hit by two suicide bombers Nov. 19, killing 23 people and wounding 145.
Lebanese security authorities identified the bombers as a Lebanese Sunni and a Palestinian Sunni from the Ain al-Hilweh refugee camp in the southern city of Sidon and a follower of fugitive Sunni preacher Ahmed al-Assir.
The camp is a hotbed of Sunni jihadists. Assir, a staunch supporter of the Sunni rebels in Syria that Hezbollah is fighting, is fiercely anti-Hezbollah.
In June, his followers in Sidon battled the Lebanese army, supported by Hezbollah fighters, for three days after a fiery anti-Hezbollah protest.
It was Lebanon's worst sectarian clash since the Syrian war erupted in March 2011 and many saw it as an ominous omen: the opening shots in Lebanon's 1975-90 civil war were fired in Sidon.
Eighteen soldiers, 40 Assir gunmen, four Hezbollah fighters and two civilians were killed.
Meantime, in northern Lebanon, the army has taken over the port city of Tripoli in a bid to end months of fighting between Sunnis and Alawites, an offshoot of Shia Islam and the minority sect that dominates Assad's Syrian regime.
Tripoli has been a sectarian flashpoint since 2007 when Sunni extremists of Fatah al-Islam fought the Lebanese army for control of the Nahr al-Bared Palestinian camp in the worst fighting since the civil war.
In three months of combat, from May 20 to Sept. 7, 450 people were killed, including 220 militants and 168 soldiers. Fatah al-Islam was mangled, but it survived and gathered strength, along with other jihadist groups, primarily in the Palestinian camps.
As the Syrian war increasingly became a conflict between Shiite Iran and Sunni Saudi Arabia, it exacerbated Lebanon's sectarian fault line.
The 1975-90 war, in which 150,000 people died, was largely a Christian-Muslim rift. Now the bloodletting's between Sunni and Shiite, an extension of a 1,400-year-old schism in Islam that is epitomized by the power struggle between Saudi Arabia and Iran, which is now the core of the violence sweeping the Middle East.
Iraq is another flashpoint where hundreds of Shiites are being killed weekly by al-Qaida. Similar bloodletting is happening in Yemen and there's sectarian friction in Saudi Arabia itself and other Persian Gulf states.
Jihadist insurgencies are taking place in Egypt and across North Africa directed not at Shiites but at other Sunnis, illustrating the breadth of the jihadist creed in the region and how it is now openly clashing with Hezbollah.
Notable deaths of 2014 [PHOTOS]