DEIR HAFER, Syria: A US military delegation arrived in a contested area of northern Syria on Friday following rising tensions between the Syrian government and a Kurdish-led force that controls much of the northeast.

The US has good relations with both sides and has urged calm. A spokesperson for the US military did not immediately respond to a request for comment.

Earlier in the day, scores of people carrying their belongings arrived in government-held areas in northern Syria ahead of a possible offensive by Syrian troops on territory held by Kurdish-led fighters east of the city of Aleppo.

Many of the civilians who fled were seen using side roads to reach government-held areas because the main highway was blocked by a checkpoint in the town of Deir Hafer normally controlled by the Kurdish-led and US-backed Syrian Democratic Forces, or SDF.

The Syrian army said late Wednesday that civilians would be able to evacuate through the “humanitarian corridor” from 9 a.m. to 5 p.m. Thursday and then extended the evacuation period another day. The announcement appeared to signal plans for an offensive against the SDF in the area.