Russian forces crossed the Euphrates River in Syria and headed for the border with Turkey, state media reported Wednesday, under a deal for the withdrawal of Kurdish forces.
The Rossiya-24 television channel and TASS news agency quoted the defence ministry as saying the convoy of Russian military police had crossed the river at noon (0900 GMT) and "advanced towards the Syrian-Turkish border".
The agreement will see Russian military police and Syrian border guards "facilitate the removal" of Kurdish People's Protection Units (YPG) fighters and their weapons from within 30 kilometres (18 miles) of the Turkish-Syrian border.
This withdrawal must be finalised within 150 hours.
It was reached after marathon talks between President Recep Tayyip Erdogan and President Vladimir Putin in Russia on Tuesday.
It will also see Turkey preserve a "safe zone" inside Syria about 120 kilometres long (75 miles) and 32 kilometres deep. Russia and Turkey will eventually launch joint patrols along the zone.