Turkey shells YPG positions near Hassa on the Syria border on 21 January 2018Image copyrightAFP Turkish ground troops have crossed into northern Syria as part of Ankara's campaign to rid the border area of Kurdish fighters, Turkey's PM says.

Binali Yildirim said the aim was to establish a 30km (19-mile) "safe zone" inside Syria, Turkish media report.
Turkey launched its operation against the Kurdish YPG militia in the Afrin region with air strikes on Saturday.
The YPG denied Turkish troops were on Afrin soil, saying they had "repelled" the attacks and forced them to retreat.