An al Qaeda linked group has said it was behind the deadly double suicide attack on the Iranian embassy in Beirut.
The blast killed at least 23 people, including an Iranian cultural attache, and hurled bodies and burning wreckage across a debris-strewn street.
Nearly 150 people were injured.
The Abdullah Azzam Brigades has threatened to inflict more carnage unless Iran withdraws forces from Syria, where they have backed President Bashar al-Assad’s over two year old war against rebels.
Iran’s foreign minister interrupted talks with his Italian counterpart to condemn the attack and issue an appeal for international aid.
“The tragedy today, two Iranians were victims of it and more and more Lebanese unfortunately than Iranians were victims of this tragedy but that should be a reminder for all of us, that should be an alarm for all of us that we need to deal with this issue and unless we deal with this issue seriously it will engulf all of us,” said Mohammed Javal Zarif.
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.
Hezbollah’s military role in Syria has helped to inflame sectarian tension there and in Lebanon.
But some sources have suggested the attack may have been an attempt to pressure Iran before Wednesday’s talks between world powers and Iran over its disputed nuclear programme.