Tens of thousands of mourners accompanied the coffin as it was driven from the American University Hospital in West Beirut to a mosque at the Shohada Cemetery a few miles away, with many in the crowd calling for revenge against Syria, widely held to be responsible, and its President Bashar al-Assad.
The 64-year-old legislator, who belonged to the majority anti-Syrian parliamentary bloc led by Saad Hariri, the son of the assassinated former Lebanese Prime Minister Rafik Hariri, is the seventh major Lebanese politician to be killed in the last two and a half years, and his death is a further setback to the country's fragile stability.
The killing comes three days after the government, acting in concert with the United Nations, began forming an international tribunal to try suspects in Hariri's murder February 14, 2005. Syria has repeatedly denied involvement in Hariri's assassination.
Prime Minister Fouad Siniora angrily denounced the killing, calling for an emergency meeting of Arab foreign ministers and beseeching the international community for help in investigating the crime.
Saad Hariri, for his part, did not wait for the outcome of an investigation and implicated Damascus directly.
Those responsible for Eido's murder are "the same ones who killed Rafik Hariri," he said. "I tell the criminals, 'you will be punished and you will be dragged to prisons and will face justice,' God willing."
He called on the members of the Arab League to "defend Lebanon" and "to boycott the terrorist regime [Syria]."
Syria, which occupied Lebanon for 29 years, is suspected by many Lebanese of trying to re-exert its control over the fractured country.
The Lebanese telecommunications minister, Marwan Hamade, himself a survivor of an assassination attempt in 2004, called the Syrian regime "a serial killer" that wants to "physically eliminate the parliamentary majority."
And an official statement by the anti-Syrian and pro-Western March 14 Movement said: "This crime is a clear signal to Lebanon from the Syrian regime in answer to the formation of the international tribunal."
The assassination comes against the backdrop of separate fighting to the north, where a four-week-long battle between the Lebanese military and al-Qaida inspired militants in a Palestinian refugee camp near the city of Tripoli has compounded the bitter power struggle between the pro-Western Siniora government and the Syrian-backed Hezbollah movement.
More than 140 people have been killed so far in the Lebanese Army siege of the Nahr el-Bared camp, with the militants inside vowing to fight to the last, and Wednesday's bombing, though far more dramatic and portentous in its impact, is merely the latest in a series of blasts to hit Beirut since the fighting at the camp erupted.
