Three other people also died and 10 were wounded in the explosion that blew up Tueni's armoured SUV in a mainly Christian neighborhood east of Beirut. Their bodies charred beyond recognition, witnesses said.

Tueni, who is also a prominent journalist, was a leading critic of Syria who was elected to parliament in this year's election.

Several cars were set ablaze and nearby shops and buildings suffered damage. Police and soldiers cordoned off the area as rescue workers ferried casualties to hospitals.

Journalist Anthony Mills called it "a scene of destruction," saying windows were broken in buildings for hundreds of meters.

"The most frightening thing about this is nobody knows why, nobody knows how, and nobody knows who's next," said Nadim Shehadi, who directs the Center for Lebanese Studies at Oxford University in Britain.

The blast comes as the U.N. investigator probing the assassination of Hariri delivered his second report to U.N. Secretary-General Kofi Annan.

This is a major loss for Lebanon and like Hariri's murder, could outrage the Lebanese and could call for a UN investigation to find out who was behind this outrageous assassination of one of the most patriotic Lebanese leaders.

Lebanon has been rocked by a series of bombings and assassinations since the February 14 killing of former Prime Minister Rafik al-Hariri.

Sources: Agencies, Local TV