
The patrols began at around midday in a village in the Al-Darbasiyah region. The soldiers headed to the east of Al-Darbasiyah in a convoy of Turkish and Russian military vehicles to patrol a strip of territory several dozen kilometres long, according to Turkish military sources.

The Russian army said in a statement that the convoy consisted of nine vehicles, protected by an armoured personnel carrier, and that it would cover more than 110 kilometres. The Turkish defence ministry confirmed that the patrols "with ground and air units are underway".

Kurdish forces were given a 150-hour deadline to withdraw from a band of territory along the border, under an agreement hammered out in the Russian Black Sea resort of Sochi last week after Turkey's cross-border offensive into Syria. The deadline expired on Tuesday evening.

As a result of the Sochi deal and another pact with the US reached a few days earlier, Turkey halted the offensive it had launched against Kurdish forces on October 9. On Tuesday Turkish President Recep Tayyip Erdogan said that Russia had informed Turkey that Kurdish People's Protection Units (YPG) fighters had withdrawn as planned.

Turkey intends to set up a "safe zone" 30 miles deep into Syrian territory in to move the YPG militia away from the Turkish border.

The YPG was a key ally in Western-backed efforts to defeat the Islamic State group but Turkey considers it a "terrorist" offshoot of the outlawed Kurdistan Workers' Party (PKK), which has been waging an insurgency inside Turkey since 1984. Erdogan has also said some of the 3.6 million Syrian refugees that Turkey is hosting could be sent to the zone.

Thanks to the operation launched in October, Turkey has now been able to establish a 120km-long zone under its control to the east of the river, between the towns of Tal Abyad and Ras al-Ain. However, Turkey's plan to extend the zone over some 450km was prevented by the presence of Syrian government forces, who were invited into other border areas by the YPG.