Two suicide bombings rocked Iran's embassy compound in Lebanon on Tuesday, killing at least 23 people including an Iranian cultural attaché and hurling bodies and burning wreckage across a debris-strewn street.
A Lebanon-based al Qaeda-linked group, the Abdullah Azzam Brigades, claimed responsibility and threatened further attacks unless Iran withdraw forces from Syria, where they have backed President Bashar al-Assad's 2-1/2-year-old war against rebels.
Security camera footage showed a man in an explosives belt rushing towards the outer wall of the embassy before blowing himself up, Lebanese officials said. They said a car bomb parked two buildings away from the compound had caused the second, deadlier explosion. The Lebanese army, however, said both blasts were suicide attacks.
In a Twitter post, Sheikh Sirajeddine Zuraiqat, the religious guide of the Abdullah Azzam Brigades, said the group had carried out the attack. "It was a double martyrdom operation by two of the Sunni heroes of Lebanon," he wrote.
Lebanon has suffered a series of sectarian clashes and bomb attacks on Sunni and Shi'ite Muslim targets which have been linked to the Syrian conflict and which had already killed scores of people this year.
Tuesday's bombing took place on the eve of more talks between world powers and Iran over Tehran's disputed nuclear program. They came close to agreeing an interim deal during negotiations earlier this month.
The bombs also struck as Assad's forces extended their military gains in Syria before peace talks which the United Nations hopes to convene in mid-December and which Iran says it is ready to attend.
Shi'ite Iran actively supports Assad against mostly Sunni rebels - two of its Revolutionary Guard commanders have been killed in Syria this year - and, along with Hezbollah fighters, it has helped turn the tide in Assad's favor at the expense of rebels backed and armed by Sunni powers Saudi Arabia and Qatar.
CULTURAL ATTACHE KILLED
"At one entrance of the Iranian embassy I counted six bodies outside," Reuters television cameraman Issam Abdullah said. "I saw body parts...thrown two streets away. There is huge damage."
The embassy's sturdy metal gate was twisted by the blasts, which Lebanon's Health Minister Ali Hassan Khalil said killed 23 people and wounded 146.
An Iranian Foreign Ministry spokeswoman said the bombs were "an inhuman and vicious act perpetrated by Israel and its terror agents", Iran's IRNA news agency reported.
Israeli lawmaker Tzachi Hanegbi said his country had played no role. "The bloodshed in Beirut is a result of Hezbollah's involvement in the Syria crisis. Israel was not involved in the past and was not involved here," he said in Jerusalem.
Iran's ambassador Ghazanfar Roknabadi identified one of the dead as Ebrahim Ansari, a cultural attaché who was on his way to work at the diplomatic compound when the bombs exploded.
Fires engulfed cars outside the embassy and the facades of some buildings were torn off. Shattered glass covered the bloodied streets and some trees were uprooted, but the embassy's well-fortified building itself suffered relatively minor damage.
"Whoever carries out such an attack in these sensitive circumstances, from whichever faction, knows directly or indirectly that he is serving the interests of the Zionist entity (Israel)," Roknabadi said.
He did not say whether other embassy officials were among the dead, but Lebanese TV stations quoted Iranian diplomatic sources as saying none of their staff in the embassy was hurt.
Britain's Foreign Secretary William Hague condemned what he described as a "shocking terrorist attack" and France expressed "solidarity with the Lebanese and Iranian authorities".
Politicians from across Lebanon's Sunni, Shi'ite and Christian communities also condemned the attack.
In Syria, the government said its soldiers took full control of the town of Qara, which straddles a highway from Damascus to government strongholds on the coast and is also used by Sunni rebels to cross into Syria from Lebanon.
The capture of Qara may mark the start of a wider offensive by the army, which has been backed by Hezbollah and Shi'ite fighters from Iraq, to recapture the mountainous border region of Qalamoun and further consolidate Assad's control of territory around Damascus and close to the Lebanese border.
Hezbollah's military role in Syria has helped inflame sectarian tension there and in Lebanon. Many Lebanese Sunnis back the Syrian rebels, while many Shi'ites support Assad, whose minority Alawite sect derives from Shi'ite Islam.
Ayham Kamel, Middle East analyst with Eurasia Group, said the embassy bombing was an attempt by supporters of the Sunni rebels to weaken Hezbollah and Iran's support for Assad, undermine the Qalamoun campaign and potentially pressure Tehran before Wednesday's nuclear talks.
"While sectarian tensions in Lebanon will increase, Hezbollah's retaliatory response will be centered on Syria where (it) will further commit military forces to eliminate the Sunni rebel threat along the Syrian-Lebanese borders," he said.
The Abdullah Azzam Brigade, which claimed the attack, has strong links in Lebanon's Palestinian refugee camps as well as connections with the Gulf - two of its senior military leaders are Saudi nationals, said Charles Lister, an analyst at IHS Jane's Terrorism and Insurgency Centre.
"This attack is a significant escalation. After months and months of speculation, an al Qaeda-linked group has now underlined its involvement in the Syria-related Lebanese theatre," he said.
Syrian Information Minister Omran Zoabi implicitly blamed Saudi Arabia and Qatar for supporting radical militants, who have been blamed for previous attacks against Shi'ite targets.
Footage from local news channels showed charred bodies on the ground as flames rose from stricken vehicles. Emergency workers and residents carried victims away in blankets.
"These kinds of explosions are a new and dangerous development," said the head of Hezbollah's parliamentary bloc in Lebanon, Mohammad Raad.
Southern Beirut, a Hezbollah stronghold, was hit by three explosions earlier this year. Those attacks were blamed on groups linked to the Syrian rebels, believed to be in retaliation for the group's military role in Syria.
Three decades ago, Iranian-backed Shi'ite militants carried out devastating suicide bombings in Lebanon that hit the U.S. embassy, as well as U.S., French and Israeli military bases.