Patrols along key M4 highway are being conducted in line with protocol between Turkey, Russia

Turkish and Russian troops have carried out the ninth joint patrol along a key highway in Idlib, northwestern Syria, Turkey’s National Defense Ministry said Thursday.

“Within the framework of TUR-RF Agreement/Protocol, the 9th TUR-RF Combined Land Patrol on M-4 Highway in Idlib was conducted with the participation of land and air elements,” the ministry said on Twitter.

The M4 highway, also known as the Aleppo-Al Hasakah road, is about 30 kilometers (19 miles) from Turkey's southern border.

The eighth joint patrol was conducted on Tuesday.

This March, Ankara and Moscow agreed on a protocol urging parties to “cease all military actions along the line of contact in the Idlib de-escalation area.”

The protocol said joint Turkish-Russian patrols would begin on March 15 along the M4 highway from the settlement of Trumba -- 2 km (1.2 miles) to the west of Saraqib -- to the settlement of Ain al-Havr.

Idlib has long been under siege by Assad regime forces and its allies, and previous ceasefires for the region were plagued by violations.

Turkey has worked to protect the local civilian population as well as rid the wider region of terrorist elements.