BEIRUT (Reuters) - Buses carrying evacuated Islamic State fighters reached Syria's Deir al-Zor on Wednesday in return for releasing a Hezbollah prisoner, a commander in the alliance fighting with Damascus told Reuters.
Damascus and Hezbollah allowed nearly 300 lightly armed militants and 300 relatives to leave the Syria-Lebanon border region in a surrender deal, after an offensive there last month.
The transfer marked the first time Islamic State militants publicly agreed to such an evacuation from territory it held.
A U.S.-led coalition had temporarily stopped the 17 buses from reaching Deir al-Zor and the convoy split in two. It was not immediately clear if all the buses arrived in Islamic State territory in Deir al-Zor on Wednesday.
"The deal has been completed," said the commander in the military alliance fighting in support of the Damascus government.
The buses took the route between the town of al-Sukhna and Deir al-Zor, a main road that the Syrian army and allied forces seized in recent days, the commander said.
Along the route, the combatants swapped the evacuees for a Hezbollah prisoner who had been in Islamic State captivity, the non-Syrian commander added.
Under the evacuation deal in August, Islamic State militants left their enclave at the border after a week-long battle in return for safe passage to Deir al-Zor province in Syria.
Lebanon's Shi'ite Hezbollah recovered the remains of some of its forces killed in Syria as part of the swap, and was meant to recover one of its fighters that Islamic State held captive.
The transfer ended any insurgent presence on the frontier, where the Lebanese army had also been fighting the militants in a separate offensive on its side of the border.
But the U.S.-led coalition fighting Islamic State blocked the convoy from entering IS territory in east Syria, near the border with Iraq, by cratering roads and destroying bridges.
The convoy split in two, with 11 buses remaining in the open desert and others retreating into government territory.
Last week, the U.S. coalition said its surveillance aircraft moved away from the buses in the no-man's land after pro-Syrian government forces "advanced past" the convoy.
(Reporting by Laila Bassam; Writing by Ellen Francis; Editing by Toby Chopra)