By John Davison
BEIRUT (Reuters) - Buses carrying Syrian militants and refugees left a Lebanese border area bound for a rebel-held part of Syria on Wednesday, under a deal made after Shi'ite Hezbollah routed Sunni Islamist Nusra Front insurgents in their last foothold at the frontier.
Some 7,000 Syrians including 1,000 militants, their families and refugees are to leave the Lebanese town of Arsal and the surrounding border area and head for Syria's northwestern Idlib province under the deal, Hezbollah-run media outlets said.
The transfer echoes deals struck within Syria in which Damascus has shuttled rebels and civilians to Idlib and other opposition areas. Such evacuations have helped President Bashar al-Assad recapture several rebel bastions over the past year, and are criticized by the opposition as amounting to the forced transfer of populations seen as sympathetic to the opposition.
The ceasefire took effect last week, just days after Lebanese Hezbollah and the Syrian army launched an offensive to drive Nusra Front and other Sunni Muslim militants from their last foothold along the Syria-Lebanon border.
The operation has highlighted the major role of Hezbollah in fighting militants along the frontier during Syria's six-year war, part of the much bigger role it has played across Syria in support of Assad.
Hezbollah's Al Manar television said that 113 buses had begun leaving Arsal town, headed for Fleita on the Syrian side.
At least 26 buses earlier left refugee camps in the nearby Jroud Arsal area and crossed to Wadi Hmeid further northeast in the direction of the Syrian frontier, it said, before their onward journey to Idlib.
Aid agencies with limited access to Arsal were not able to say where many of the Syrian refugees living in the area had originally come from.
Two former residents of Arsal said most refugees originally fled to Arsal when the Syrian army backed by Hezbollah took control of their towns across the border during heavy fighting over three years ago.
They said they were going to Idlib with many refugees feeling no longer safe to stay in Arsal camps after Hezbollah extended greater influence in the area while a return to government run-areas would also mean they risk being drafted into the army
Abu Yahya al Qalamouni who was in touch with several refugees said "many wanted to go to a camp where Hezbollah was not in control and not for love of Idlib".
The U.N. refugee body said in a statement it was not party to the agreement and stressed that "return of refugees should be made free from undue pressure."
"The UNHCR is not in a position to ascertain to what extent refugees, who are civilians by definition, are returning in this movement," it said.
The deal included the release of eight Hezbollah fighters by the Nusra Front in exchange for individuals held by Lebanon. Three of the Hezbollah fighters were released overnight. The remaining five are expected to be released once the first convoy reaches its destination in Syria.
Last week, Hezbollah captured most of the mountainous zone of Jroud Arsal from the militants. It also has a strong presence on the Syrian side of the border where its fighters alongside pro-government militias maintain security in a string of Syrian towns and villages in the areas known as Western Qalamoun.
The Nusra Front was al Qaeda's Syria branch until it severed ties and rebranded last year. It now spearheads the Tahrir al-Sham Islamist alliance in the Syrian civil war.
The Lebanese army, which receives considerable U.S. and British military support, did not take an active part in the operation, setting up defensive positions around Arsal.
The next phase is expected to focus on a nearby enclave currently in the hands of Islamic State jihadists. Local media say the Lebanese army will likely wage that phase of the operation.
Hezbollah's role in Syria's conflict has been criticized by its Lebanese political opponents, including Prime Minister Saad al-Hariri, who is a Sunni.
Iran-backed Hezbollah, which has lost hundreds of fighters in Syria, says its fight is an existential one to stop extremists spreading to Lebanon. Its Lebanese critics say it has fueled militant attacks in Lebanon.
The Arsal region witnessed one of the most serious spillovers of the Syrian civil war into Lebanon when Nusra Front and Islamic State militants briefly overran the town of Arsal in 2014, abducting dozens of Lebanese soldiers and policemen.
Islamic State is still holding nine Lebanese soldiers captured at that time. Their fate is unknown.
(Additional reporting by Tom Perry and Suleiman al Khalidi in Amman Editing by Mark Heinrich and Robin Pomeroy)