Buses carrying around 7,000 Syrians began crossing into northern Syria late Thursday following a cease-fire struck by Lebanon's Hezbollah movement and the Jabhat Fateh al-Sham group.
The convoy of 117 buses arrived in Idlib province, leaving Lebanon's flashpoint town of Juroud Arsal near the border.
The cease-fire, which went into effect late last month, calls for the departure of fighters from Jabhat Fateh al-Sham, formerly known as the Nusra Front, in exchange for the release of three Hezbollah fighters captured in Syria last year while they were fighting alongside Assad regime forces.
The group, including the members of Jabhat Fateh al-Sham group and refugees, is expected to be placed in guesthouses and refugee camps.
The Humanitarian Relief Foundation (IHH) supplied them with emergency food packs and tents, Turkey's IHH field coordinator Mehmet Şuayip Altun told Anadolu Agency.
"Lebanon is on the verge of great changes and it might be subject to an embargo by the West and the Arab world due to the Hezbollah," said Nohad Machnouk, the Lebanese Interior Minister.
Backed by Syrian fighter jets, Hezbollah in mid-July began fighting several armed Syrian groups, including Jabhat Fateh, in and around Juroud Arsal.
During the fighting, human rights groups had voiced concern for the safety of some 100,000 Syrian refugees living in the region.
Syria has been locked in a vicious civil war since early 2011, when the Assad regime cracked down on pro-democracy protests with unexpected ferocity.
Since then, hundreds of thousands of Syrian civilians have been killed, according to UN officials.
The Syrian regime, however, says the total number of those killed in the conflict is much lower.