Lebanese authorities identified the second man involved in the deadly attack on the Iranian embassy in Beirut on Tuesday which killed 23 people as a Palestinian with ties to a fugitive Lebanese cleric, Reuters reported Saturday.

The Lebanese media network LBC International named him as Adnan Moussa Mohammad from the Ain al-Helweh refugee camp, the largest in Lebanon.

Lebanese government officials said he was as a follower of a firebrand Sunni preacher known for his anti-Iran rhetoric.

The suspect’s link to Sheik Ahmad al-Assir, known for his fiery sermons denouncing Iran’s Lebanese Shi’ite ally Hezbollah, is likely to increase already taut tensions between the country’s two largest Muslim sects.

Mohammad’s father was currently being held by Lebanese security authorities for questioning, LBC reported Saturday. The father had reported his son’s disappearance several months ago.

Mouin Abu Daher, a Lebanese man, was identified Friday as the first suicide bomber in the attack. Investigators from Lebanon’s military courts matched Abu Daher’s DNA to his father’s, the official said. He spoke on condition of anonymity because he wasn’t allowed to release the information.

Tuesday’s attack targeted the Iranian embassy in an upscale Shi’ite-dominated neighborhood of the Lebanese capital, killing 23 people, including a 54-year-old Iranian diplomat, Ibrahim Ansari, who oversaw regional cultural activities.

An al-Qaeda-linked group, the Lebanese Abdullah Azzam Brigades, claimed responsibility for the attack, one of the deadliest in a series of attacks targeting Hezbollah and Shi’ite strongholds in Lebanon in recent months.

They said it was payback for the military support that Iran and Hezbollah provide to the Syrian government of Bashar Assad against the mainly Sunni rebels fighting to overthrow his rule.

The Syrian conflict, in its third year, also has become a confrontation between regional powers, mainly Iran and Saudi Arabia.

It has also created tensions in Lebanon over Hezbollah’s open participation in the conflict to shore up Assad forces.

That has deepened sectarian tensions in Lebanon between Sunnis, who tend to support the rebels, and Shi’ites, who tend to support Assad.

The charismatic Sheik al-Assir and his hard-line supporters battled Lebanese soldiers, supported by Hezbollah fighters, in days of clashes in July. Security officials say the preacher is at large, having eluded attempts by Lebanese officials to arrest him.

The SITE Intelligence Group which monitors jihadi threats said Abu Daher was a fan of hard-line al-Qaeda linked websites and vowed he would die in a suicide bombing. They published a photo claimed to be Abu Daher, showing a young muscular man with a bushy beard and black cap characteristic of hard-liners.