Eido was a vocal critic of the Syrian regime, and his assassination in a seafront attack on Wednesday stoked fears of instability in a country battling deep sectarian and political divisions.

Syria has so far made no official comment on his assassination, with the official press merely reporting the incident.

But the Al-Watan daily, which describes itself as independent, "directly accuses the (anti-Syrian) parliamentary majority of having sacrificed MP Eido in order to continue its destructive project in Lebanon."

Thousands of people, led by parliamentary majority leaders Saad Hariri and Walid Jumblatt, marched from the family home toward a mosque in southeast Beirut for mid-day prayers and then burial in a nearby cemetery.

"Beirut wants revenge on (pro-Syrian Lebanese President Emile) Lahoud and (Syrian President) Bashar (Assad)," cried mourners marching behind ambulances carrying the coffins of the Beirut MP, his son and a bodyguard who were killed with him.

"With our soul, with our blood we shall redeem you Saad," chanted the mourners, amid a sea of hands, which carried the coffins draped with Lebanese flags into the Khashokji mosque.