Scores of civilians carrying their belongings arrived in government-held areas in northern Syria on Friday amid fears of a potential Syrian army offensive against Kurdish-led fighters east of Aleppo.

Many used side roads after the main highway was blocked at a checkpoint previously controlled by the Kurdish-led and U.S.-backed Syrian Democratic Forces (SDF), AP journalists reported.

The Syrian army had announced late Wednesday that civilians could use a "humanitarian corridor" from 9 a.m. to 5 p.m. Thursday, signaling possible plans for an operation against the SDF east of Aleppo. Limited exchanges of fire were reported between the two sides.

Men, women, and children arrived in cars and pickup trucks loaded with clothes, mattresses, and other belongings. Local officials guided them to shelters. Some crossed canals by small boats or used a damaged pedestrian bridge to reach government-held areas.

Despite the SDF closing the main highway, about 4,000 people managed to reach government-controlled zones via alternative routes, according to Syrian state TV.

A U.S. military convoy reached Deir Hafer in the early afternoon, though it was unclear if the personnel would remain. Washington maintains good relations with both sides and has urged calm.

Inside Deir Hafer, most shops were closed and residents stayed indoors. Umm Talal, who arrived with her husband and children, said the road appeared safe and her husband planned to return home. Abu Mohammed, coming from Maskana, said SDF fighters had blocked the main highway, forcing people onto side roads.

The tensions follow heavy clashes last week in Aleppo, which ended with Kurdish fighters evacuating three northern neighborhoods that were then taken over by government forces. Fighting erupted as talks stalled between Damascus and the SDF over a March agreement for integration of forces and government control of institutions, including border crossings and oil fields in the northeast.

U.S. Special Envoy Tom Barrack said on X that Washington is in close contact with all parties, working to "prevent escalation and return to integration talks between the Syrian government and the SDF."

The SDF has long been Washington’s main partner in the fight against ISIS, but Turkey considers it a terrorist group due to its links with Kurdish separatists.