Lebanese authorities have identified one of the suicide bombers who attacked the Iranian embassy in Beirut this week as a Lebanese Islamist, a security source said on Friday.

The man was from the southern port city of Sidon, and was known to have had links with Islamist groups, the source said.

His family were asked to meet security forces for a DNA test to confirm their relationship with the bomber, and to pick up his remains, he said.

Twin blasts at the embassy on Tuesday killed 23 people, including the Iranian cultural attache, and wounded 146 others.

The attack was claimed by the Al-Qaida-linked Abdullah Azzam Brigades, which threatened more attacks if Iran did not end its involvement in the 2-1/2-year-old Syrian conflict. 

The civil war that has divided Syria along sectarian lines has frequently spilled over into its smaller neighbor, with its own fragile sectarian balance. 

Syria's revolt is led by the Sunni Muslim majority, while President Bashar Assad draws most of his support from members of the Alawite sect, an offshoot of Shi'ite Islam. He is also getting money and military support from Tehran. 

The Lebanese Shi'ite guerrilla group Hezbollah, also funded by Iran, has sent fighters into Syria to help Assad. Hezbollah-controlled areas in southern Beirut have been hit by blasts three times this past year.