BEIRUT -- A double suicide bombing of Iran's embassy in Lebanon that killed at least 23 people and wounded hundreds of others sent shockwaves of fear across this capital city Tuesday that Syria's civil war would trigger violence not seen since this country's own civil war two decades ago.
A mysterious local franchise of al-Qaida took responsibility for the attack and said similar attacks would continue until Iran and its Lebanese Shiite ally, Hezbollah, withdraw their fighters from Syria, where they have played a crucial role in turning the tide of battle in favor of President Bashar Assad.
Many in Beirut feared that the Shiite militant group would retaliate and push Lebanon into further sectarian violence.
Mahmoud Komati, a senior Hezbollah official at the scene, described the bombings as a "message of blood and death" from al-Qaida-styled militants fighting to topple Mr. Assad. Mr. Komati said the attack was a response to the "successive defeats suffered by [jihadists] in Syria."
With pro-Assad forces racking up victories throughout Syria in recent months, the group that claimed responsibility for the blast, the al-Qaida-affiliated Abdullah Azzam Brigades, promised more attacks until Hezbollah's and Iran's forces leave Syria. In a statement, Azzam spokesman Sirajuddin Zurayqat called the suicide attacks' perpetrators "Lebanese Sunni heroes" and said "operations in Lebanon will continue" until Hezbollah units have left Syria and Azzam prisoners are released by Lebanese authorities.
In Washington, Secretary of State John Kerry condemned the attack, calling it "senseless and despicable." He pledged that the United States would continue its support to the Lebanese government and urged all parties to cooperate with the investigation. "The United States knows too well the cost of terrorism directed at our own diplomats around the world, and our hearts go out to the Iranian people after this violent and unjustifiable attack," he said.
Both witnesses and the Lebanese army described the attack as following what has become a familiar one-two punch for terrorists: The first attacker, riding a motorcycle packed with a small explosive charge, targeted the embassy's heavy external security, followed a few moments later by a much larger bomb carried by a car that targeted the building itself.
"There was an explosion, then after a bit, another much larger explosion," said Mahmoud Abbas, who sells coffee from a pushcart near the embassy.
Although the area around the embassy is seen as broadly supportive of Hezbollah, the building is not located in one of Hezbollah's special "security zone" neighborhoods, which have been under massive security precautions since several rocket and car bomb attacks in early summer. But the kind of tight security precautions that prevail in those security zones, where nearly every car is searched and traffic is frequently banned, were not in place in the affluent area where the embassy is located.
"Embassies have to be open; they're very hard to protect," a harried Hezbollah security official said in a brief phone call after the blast, speaking on condition of anonymity because he was not authorized to speak publicly.
The Lebanese Health Ministry said at least 23 bodies had been recovered, and that a search for additional victims continued. Local media said at least 200 people were wounded in the blast.
Initial reports that Iran's cultural attache had been killed were later retracted, as the Iranian ambassador to Lebanon, Ghazanfar Roknabadi, announced that Sheikh Ibrahim al-Ansari had suffered severe head wounds but had survived. At least two Iranian and several Hezbollah security personnel died in Tuesday's attacks, according to local security officials.
The explosion reinforced a widespread belief among Lebanon's strongly pro-Hezbollah Shiite population that it would remain a target of jihadist groups that have flooded Syria to take part in the anti-Assad insurgency.