BEIRUT — A large bomb exploded in the heart of Beirut’s Christian section Friday, killing a top Lebanese security official and at least seven others, wounding dozens, and spreading anxiety and dread in a city where memories of sectarian violence from Lebanon’s long civil war have been resurrected by the conflict in neighboring Syria.
The security official, Brigadier General Wissam al-Hassan, was apparently the intended target of the explosion, which ripped into buildings, upended cars, and shattered windows for blocks in the most serious bombing to hit Beirut in at least four years. He was declared dead a few hours after the blast in an announcement on Lebanese television.
As the intelligence chief of Lebanon’s Internal Security Forces, Hassan played a leading role a few months ago in the arrest of a former information minister, Michel Samaha, who had close ties with the Syrian leadership and was accused of plotting a campaign of bombings and assassinations in Lebanon. Samaha’s arrest was widely seen as part of Lebanese government efforts to prevent the spread of sectarian mayhem in the country.
Hassan, a Sunni Muslim, also was close to the family of Rafik Hariri, the Sunni former prime minister who was assassinated in a 2005 car bombing in Beirut that Hariri’s supporters have blamed on Syria and its Lebanese allies. The bombing Friday came a day after Hassan returned from a trip to Germany and France. He had moved his family to Paris in the aftermath of Samaha’s arrest because he had received numerous threats.
The identities of the other victims in the bombing were not immediately clear, and there was no word on who was behind the blast, which the authorities said had been caused either by a car bomb or a bomb hidden in the street or under a vehicle parked in the affluent Sassine area, two blocks from a gleaming shopping center.
It exploded midafternoon just as the school day was ending.
Suspicion quickly fell on groups aligned with Syria’s president, Bashar Assad, the embattled leader who has long been an influential political force in Lebanon and is close with Hezbollah, the militant Shi’ite
Lebanese organization that is a powerful faction in Lebanon’s own complex web of politics. The offices of two Lebanese political groups that oppose Assad, the Christian Phalange Party and the March 14 alliance, are in the same area as the blast site.
‘‘It is clear that the Syrian regime is responsible for such an explosion,’’ said Nadim Gemayel, a member of Parliament and senior member of the Phalange Party, whose father, Bashir Gemayel, was assassinated in an explosion at party headquarters in 1982 just a few weeks after he was elected president. ‘‘It is such a big explosion that only the Syrian regime could have planned it.’’
Hariri’s son, Saad, who also is a former prime minister, and Walid Jumblatt, the longtime leader of Lebanon’s Druze community, also accused the Syrian government of responsibility for the bombing.
Both the Syrian government and Hezbollah rejected the accusations. The official Syrian Arab News Agency in Damascus quoted Omran al-Zoubi, the information minister, as saying the bombing was a ‘‘cowardly terrorist act,’’ while in Beirut, Hassan Fadlallah, a Hezbollah member of Parliament, said that his organization condemned the bombing and that such acts target all Lebanese.
‘‘Let’s wait for an investigation to reach the truth,’’ he said.
The emotional shock and anxiety from the blast had evolved into outrage in some areas by late Friday evening, with reports of protests by Sunnis who blocked streets and set fire to tires.
Agence France-Presse said one of its correspondents witnessed an angry demonstration on the road between the northern city of Tripoli and the Syrian border.
Terraces on apartment buildings were sheared off by the force of the blast, which shattered glass on structures several blocks away. One car’s blackened and ripped hulk appeared to have been thrown on top of another.
Shutters were askew on a traditional Lebanese house across the narrow street. Fire trucks, ambulances, police officers, and soldiers crowded the neighborhood.
The explosion shook the neighborhood just before 3 p.m., sending black smoke rising over the Sassine area, a wealthy shopping and residential district. Beirut cellphones were jammed as people spread the news.
Wounded people, many of them elderly residents of the neighborhood, were emerging from houses, sobbing.