BEIRUT Hundreds of rebels from northern Syria managed to enter the besieged city of Qusair on Friday, activists said, to help opposition forces battling government troops backed by the Lebanese group Hezbollah.
The Syrian Observatory for Human Rights said hundreds of fighters from the Tawheed brigade, an Islamist group that is powerful in Aleppo in the north, had entered the town.
The brigade confirmed the report on its Facebook page.
The two-week battle for Qusair is aimed at securing supply routes near the Syrian-Lebanese frontier, which both sides accuse the other of using to bolster their forces inside Syria.
For Syrian President Bashar al-Assad, seizing Qusair would also allow him to cement control of a belt of territory between the capital Damascus and his stronghold on the Mediterranean coast.
Fighters coming to support Qusair's embattled rebel forces had been bogged down for days on the outskirts of the town, once home to about 30,000 people.
Rebels have lost more than two-thirds of the town to Assad and Hezbollah forces, but say they are still hunkered down in central Qusair. They had faced a tight blockade that prevented fighters or supplies from entering and the wounded from leaving.
Rami Abdelrahman, head of the Observatory, said it was unclear whether or not the fresh influx of Tawheed fighters was enough to help the opposition regain some lost ground.
"It is too soon to tell if they can make a difference. We will have to watch today and see if they can help the fighters create a turning point," he told Reuters by telephone.
Syria's bloody conflict, now in its third year, began as peaceful protests against Assad's rule but devolved into civil war after a fierce security crackdown.
The fighting, particularly in battles such as Qusair, has stoked sectarian tensions and has become increasingly regionalised.
Syria's Sunni Muslim majority, as well as Sunnis from across the region, have largely supported the revolt. Minorities, fearing Islamist groups, have generally backed Assad, who has also drawn substantial backing from Shi'ite Iran.
Shi'ite Hezbollah, a guerrilla group with battle experience fighting its sworn enemy Israel, is now openly operating in Syria on behalf of Assad and its fighters have been spotted in several areas across the country.
Dozens of Hezbollah fighters have died in and around Qusair, while hundreds of rebels have been killed in the clashes.
(Reporting by Erika Solomon; Editing by Crispian Balmer)