Syria has been blamed for a car bombing in Beirut that killed a prominent Lebanese security official and seven others.

Saturday's blast, the worst the Lebanese capital has seen in more than four years, wounded 86 people and was seen as a sign that Syria's war is spilling over the country's borders.

When asked who he thought was responsible for the killing, Saad al-Hariri, leader of the opposition March 14 alliance, replied: "Bashar Hafez al-Assad," referring to the Syrian president.

"Who killed Wissam al-Hassan is as clear as day. Certainly the Lebanese people will not be silent over this heinous crime and I, Saad Hariri, promise that I will not be silent."

Walid Jumblatt, Lebanon's Druze leader, also accused Assad of being behind the attack.

"The Syrian regime is expert in political assassinations," he told the AFP news agency. "Our response needs to be political. A president who burns Syria and is the executioner of Damascus does not care if Lebanon burns."

The attack in the Ashrafiyeh neighbourhood killed Wissam al-Hassan, intelligence chief of the Internal Security Forces (ISF), who led an investigation that implicated Syria and Hezbollah in the assassination of former prime minister Rafik al-Hariri, Saad al-Hariri's father.

He also headed an investigation over the summer that led to the arrest of former Information Minister Michel Samaha, an ally of Assad, accused of trying to help smuggle explosives into Lebanon.

Syrian condemnation

Syrian Information Minister Omran al-Zohbi condemned what he called a "terrorist, cowardly" attack. Such incidents were "unjustifiable wherever they occur," he said.

Al Jazeera's Rula Amin, reporting from Beirut, said the blast scene was still cordoned off on Saturday morning and security was tight.

Protesters angered by the killing have blocked several roads in Beirut and in the southern city of Saida with burning tires.

Following the attack, clashes also occurred in the northern Lebanese city of Tripoli on Friday between the rival districts of Jabal Mohsen and Bab al-Tabbaneh, leaving one person dead.

Jabal Mohsen is resided by mostly Alawites supportive of Assad, while Bab al-Tabbaneh is a Sunni area.

PHOTO CAPTION

Lebanese rescue workers, remove rubble from a building that was damaged by an explosion in the mostly Christian neighborhood of Achrafiyeh, Beirut, Lebanon, Friday Oct. 19, 2012.

Al-Jazeera