BEIRUT, Lebanon — A massive double suicide bombing ripped through a Damascus neighborhood Thursday, killing 55 people, wounding more than 400 and heightening concerns that radical Islamist groups are infiltrating the Syrian uprising.
It was the deadliest bombing yet in the capital and added a sinister new dimension to the 15-month-old revolt against President Bashar Assad's rule. The method strongly recalled large-scale attacks by an Iraqi branch of al-Qaida during the height of the violence in Iraq.
As details of the attack emerged throughout the day, U.S. officials said they were increasingly convinced of an al-Qaida connection, noting that the bombing bore many of the terrorist group's hallmarks.
According to Syrian state media, two suicide bombers driving cars detonated more than 2,000 pounds of explosives, moments apart, near an intersection on a busy highway during the morning rush hour, a tactic often used in Iraq to penetrate the defenses protecting key buildings.
In this instance, the target was a headquarters of the Syrian security services' widely feared Palestine Branch, which was badly damaged in the explosion. The branch, which was thought to house many political prisoners, was the target of a rare bombing in 2008 and had since been barricaded off from the nearby highway.
Most of the casualties were civilians caught in the surrounding traffic as they headed to work or school. State television broadcast grisly pictures of charred, mangled bodies incinerated in cars and body parts strewn amid the smoldering wreckage of vehicles and piles of broken glass.
The scenes of devastation, broadcast repeatedly throughout the day on state television, seemed to signal an ugly new twist to the violence that has convulsed the country since the initially peaceful uprising began in March last year.
The attack also raised tensions linked to a fraying U.N.-mandated cease-fire that went into effect April 12 but has failed to halt the violence.