Lebanese authorities have identified one of two suicide bombers who attacked an Iranian cultural centre in Beirut this week as a radical Sunni Muslim Palestinian, a security source said Friday.
The news emerged as the toll from Wednesday's double car bombing rose to 11, after a woman died of her wounds.
"One of the suicide bombers involved in the attack in Bir Hassan has been identified as Nidal Mughayer, a 29-year-old from Al-Bisariya," in south Lebanon, the source said.
The army said he had been identified through DNA testing.
Mughayer was a follower of radical Sunni cleric Ahmed al-Assir, the security source said.
Assir has been at large since escaping fierce clashes between his supporters and the army in the southern city of Sidon last summer.
Some of his backers are believed to have fled to Syria after the clashes, and two were implicated in a double suicide bomb attack against the Iranian embassy in Beirut in November.
News of Mughayer's identity spread quickly to his predominantly Shiite home town with a small, mostly Palestinian, Sunni population.
Some residents attacked Mughayer's family home and set fire to several vehicles owned by the family, the source said.
Wednesday's attack was claimed by the Abdullah Azzam Brigades, a jihadist group inspired by Al-Qaeda that also claimed the November embassy bombing.
The group said it was to punish Lebanon's powerful Iran-backed Shiite group Hezbollah and Tehran for their role in the conflict in neighbouring Syria.
Both Hezbollah and Iran back Syria's President Bashar al-Assad, who is battling a Sunni-led uprising.
Extremist groups have claimed responsibility for a series of attacks against areas of Lebanon considered strongholds of Hezbollah that have killed dozens of civilians.
Late Thursday, Syria's interior ministry said it was willing to "cooperate with the Lebanese interior ministry in the fight against terrorism," according to state news agency SANA.
It was ready to "provide all possible means to prevent terrorist attacks that target the security and safety of the brotherly Syrian and Lebanese people."
Syria's government refers to all those seeking its overthrow as "terrorists."