Samir Kassir’s death has stunned a country that had begun to believe that the violence of recent months had ended with Syria’s military and political disengagement in April. The killing came four days after Lebanon embarked on a four-week round of elections in which the anti-Syrian opposition is expected to triumph.

Mr Kassir, 45, died instantly in the explosion, moments after he had left his home in the Christian Ashrafieh district. “He crossed the road, got into the car, turned the key and the car blew up,” a witness said.

The journalist, a veteran columnist for An-Nahar newspaper, was a staunch opponent of Syria’s long-running hegemony of Lebanon and a supporter of democracy in the Middle East. His death has chilled Lebanon’s journalistic community, the Arab world’s most vibrant and outspoken.

Malek Mrowe, a prominent businessman who had dined with Mr Kassir the previous evening, said: “Samir was very optimistic. He said, ‘Now the Syrians have gone we can say whatever we want. Lebanon will be the democratic model for the region.’”

Najib Mikati, the Lebanese Prime Minister, visited the scene of the blast and said: “Every time Lebanon takes a step forward there are those who want to undermine this country.”

Saad Hariri, whose father Rafik, a former Prime Minister, was killed in February triggering the popular backlash that led to Syria’s withdrawal, called Mr Kassir’s murder a “terrorist crime” and vowed to track down the perpetrators.

Opposition figures were swift to blame Syria and its allies in Lebanon. “Bashar al-Assad and Emile Lahoud are behind it,” said Marwan Hamade, an opposition leader who survived an attempt on his life in October, referring to the Syrian and Lebanese Presidents. He added: “Samir Kassir was a defender of democracy in the Arab world and a courageous journalist who confronted dictatorships, especially the joint dictatorship established by Lebanon and Syria.”

Rafik Shelala, a spokesman for President Lahoud, called Mr Kassir’s murder a grave incident and said that the President had ordered an investigation. Syria issued an official denial of involvement.

The pro-Syrian camp in Lebanon has withered since Damascus’s disengagement from Lebanon. Some opposition figures have called for the resignation of President Lahoud, Syria’s most faithful ally, as the first order of business of a new government after the elections. Mr Kassir’s death is likely to strengthen that demand.

With Syrian troops out of Lebanon and the Lebanese intelligence services undergoing a purge of pro-Syrian chiefs, however, many Lebanese are asking what is to be gained from further violence against opposition figures.

Chibli Mallat, a lawyer and democracy campaigner, said that Mr Kassir’s murder fitted into a pattern of repression in Syria that has been unfolding over the past two weeks.

Despite withdrawing from Lebanon in accordance with a UN resolution, Syria remains under intense pressure from America over other issues. Since the withdrawal from Lebanon, Damascus has tightened its grip at home. Several opposition activists have been detained in an apparent crackdown ahead of a key three-day conference of the ruling Baath Party in Damascus on Monday.

The conference is seen as a make-or-break opportunity for the regime to usher in crucial and long-awaited reforms. But the latest crackdown on dissenters in Syria and the murder of Mr Kassir has dampened hopes of meaningful ones.

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