By Laila Bassam and Lisa Barrington
BEIRUT (Reuters) - Three recently captured fighters from Lebanon's Hezbollah group were released by Syrian Nusra Front militants early on Wednesday in exchange for three individuals held by Lebanon, Major General Abbas Ibrahim, head of Lebanon's General Security, told Reuters.
The completed exchange means that a delayed transfer of around 10,000 Syrian militants, their families and other refugees by bus from Lebanon into rebel-held Syria is expected to begin on Wednesday morning, Ibrahim said.
The transfer was agreed under a ceasefire deal between Hezbollah and Nusra last week but delayed by two days while negotiations over the captive exchange took place.
Ibrahim said 120 militants carrying personal weapons would be among the thousands of Syrians set to leave for Syria's rebel-held Idlib province on Wednesday.
Another five captive Hezbollah fighters would then be released once the first convoy reaches its destination in Syria, Ibrahim said.
Ibrahim told Reuters that Lebanese authorities had received the three Hezbollah fighters and had handed over three individuals detained in Lebanon requested by the Nusra Front just before 1 am Beirut time (2200 GMT).
Two of the individuals handed to Nusra Front by Beirut were prisoners and one had finished his prison term.
Last week, Lebanese militia Hezbollah took most of a mountainous area straddling the Syria-Lebanon border, called Jroud Arsal, in a joint offensive with the Syrian army to drive Nusra Front militants from the area.
The Lebanese army, which receives considerable U.S. and British military support, did not take an active part in the Jroud Arsal operation, setting up defensive positions around the town of Arsal.
Hezbollah supports Syrian President Bashar al-Assad in his country's more than six-year-old conflict.
Hezbollah's role in Syria's conflict has been criticized by its Lebanese political opponents, including Prime Minister Saad al-Hariri. Hariri has previously said refugee returns from Lebanon to Syria should be coordinated only through the United Nations.
On Wednesday Ibrahim said Hariri had asked Abbas to make a success of this deal, local media reported.
(Reporting by Laila Bassam and Lisa Barrington; Writing by Lisa Barrington; Editing by James Dalgleish)