People shouted for help on Thursday after a car bombing south of Beirut, Lebanon, the deadliest blast in the country in more than eight years.  BEIRUT, Lebanon â A blast from a powerful car bomb tore through a southern suburb of this city on Thursday, killing at least 18 people and wounding nearly 300 in the heart of a stronghold of Hezbollah, the militant Shiite movement that has the countryâs strongest military force.  The evening blast, which set apartment buildings ablaze and scattered bodies in the street, was the deadliest bombing in Lebanon in more than eight years and raised fears that the country was slipping into a new era of political violence.  Lebanonâs caretaker prime minister, Najib Mikati, declared Friday a national day of mourning.  There were no credible claims of responsibility, but many here saw the bombing â and a similar attack nearby last month â as spillover from the civil war in neighboring Syria. Hezbollah has become increasingly involved there, sending fighters to back President Bashar al-Assad against the predominantly Sunni rebels seeking his overthrow. That involvement has enraged Sunnis in both countries, and many said they suspected that extremists among them had used the blasts to strike back.  âIt was clear that this was an attack on Hezbollah,â said Moussa Ghamloush, 54, who was standing outside his restaurant, around the corner from the blast site. He had been in the kitchen when the explosion âshook the earthâ and sent glass flying.  âThis is all because of the fighting in Syria,â Mr. Ghamloush said, accusing Al Qaeda and an extremist Syrian group linked to it, the Nusra Front.  The explosion, near a complex often used for Hezbollah rallies in the Ruwais neighborhood, tore a hole in the street between two tall apartment buildings, blew the fronts off shops and burned a dozen cars, flipping some on top of others. Witnesses reported seeing bodies in the street afterward, one hanging from some scaffolding down the block.  Fires raged inside the buildings, and smoke poured from their blown-out windows. Fire trucks packed the streets, as men from the neighborhood, some wielding automatic rifles, tried to clear the streets to allow water trucks to enter and ambulances to leave with the dead and wounded.  The fires and damage to the buildings made it hard for rescue crews to evacuate residents. Hours after the blast, men wearing face masks to block the smoke were still searching the upper floors with flashlights, taking residents to windows to be lowered to the street in the fire trucksâ elevator towers.  Hezbollahâs control of the area, where most residents are Shiites, is clear. Large posters of the groupâs âmartyrsâ adorn lampposts, and after the blast, men belonging to the movement, carrying guns and walkie-talkies, blocked the main highway exit leading to the site and many roads nearby.  When asked whom they blamed for the blast, many residents listed the groupâs enemies: Israel, against which it has fought numerous wars; Al Qaeda, which considers Shiites heretics; Syriaâs rebels, which resent the groupâs support for Mr. Assad; and the Persian Gulf states Saudi Arabia and Qatar, which support the Syrian uprising.  Talal Atrissi, a Lebanese political analyst, said he did not rule out Israeli involvement. Israel, along with the United States and the European Union, considers Hezbollah a terrorist organization, and it has assassinated many of its leaders. The bombing took place one day before Hezbollahâs annual commemoration of its one-month war with Israel in 2006.  But he said there were plenty of others who wanted to harm the group, mostly Sunnis who oppose its involvement in Syria. âHezbollah has many enemies,â he said. âIt is an open war against Hezbollah.â  Aware of the threat, Hezbollah had stepped up security in the area, residents said, after the bombing last month, in the nearby neighborhood of Bir al-Abed, which wounded more than 50 people.  A Sunni resident who asked that his name not be published out of fear of Hezbollah said that after the July attack, Hezbollah members checked every outsider who entered the area and passed out business cards with phone numbers that residents could call to report strangers. Residents said the attack on Thursday did not affect their support for the group.  âThey donât want Hezbollah here,â said Bushra Hijazi, who lives nearby. âBut as long as Hezbollah is here, we feel safe.â  The attack was the deadliest in Lebanon since a car bombing in February 2005 killed the countryâs prime minister, Rafik Hariri, and 22 others. Last October, a car bombing in a Christian neighborhood in Beirut killed a powerful intelligence official who was viewed as an enemy of Syria, along with seven others. Many suspected that Syria and Hezbollah had planned the attack.
The blast wounded hundreds of people in the southern suburbs of the Lebanese capital and might have been aimed at Hezbollah.