In this photo from the Syrian official news agency, people welcome Syrian troops entering the town of Ain Issa on Monday. (SANA/AP)
A Turkish-backed Syrian fighter peeks through a hole during clashes Monday in northeastern Syria. (Nazeer Al-Khatib/AFP/Getty Images)
Smoke rises Monday from the Syrian town of Ras al-Ain on the sixth day of Turkey's offensive against Kurdish forces. (Ozan Kose/AFP/Getty Images)
Syrian government troops moved back into towns for the first time in years after U.S.-allied Kurdish fighters, in a stunning reversal, reached a deal with the government. Turkish-backed rebels have begun a push to retake the northern city of Manbij, which has long been a flash point.