Lebanon's Hezbollah hands over suspected killer of Irish UN peacekeeper: security source
Private Sean Rooney, 23, was killed and three others injured on December 14 when their UN Interim Force in Lebanon (UNIFIL) vehicle was attacked near the village of Al-Aqbiya in the country's south, a stronghold of the Iran-backed group.
UNIFIL acts as a buffer between Lebanon and Israel and operates near the border.
"The main shooter has been arrested by security forces after Hezbollah handed him over hours ago," the security official said, declining to be identified because he was not authorised to speak to the media.
It was not immediately clear if the individual arrested was a member of the group.
Hezbollah is cooperating in the probe led by Lebanese military intelligence, the official said, adding that "preliminary investigations are nearly complete."
Earlier this week, a judicial official told AFP that Lebanese investigators had identified suspects in the attack, adding that there were "at least two" shooters.
A car carrying armed men followed the UNIFIL vehicle, the judicial source had said, citing preliminary findings and calling the attack "premeditated".
Hezbollah has repeatedly denied involvement in the incident, and its security chief Wafic Safa has described the killing as "unintentional".
Witnesses said villagers in the Al-Aqbiya area blocked Rooney's vehicle after it took a road along the Mediterranean coast not normally used by UNIFIL.
Al-Aqbiya is just outside UNIFIL's area of operations, the force has said.
The three passengers were injured when the vehicle hit a pylon and overturned.
Over the years, there have been a number of incidents between Hezbollah supporters and UN peacekeepers but they have rarely escalated.
UNIFIL has urged Beirut to ensure a swift investigation into the first violent death of one of its peacekeepers in nearly eight years.
The force was set up in 1978 to monitor the withdrawal of Israeli forces after they invaded Lebanon in reprisal for a Palestinian attack.
Israel withdrew from south Lebanon in 2000 but fought a devastating 2006 war with Hezbollah and its allies.
Lebanon and Israel remain technically at war.