Turkish and Russian military forces have carried out another joint patrol along a key highway in northwestern Syria, Turkey's Defense Ministry said Tuesday.

"The fifth combined Turkish-Russian land patrol was conducted today by air and ground vehicles on the M4 motorway in Syria's Idlib province, as part of the earlier TR-RF agreement," 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.

Last month, 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" starting on March 6.

The protocol said joint Turkish-Russian patrols would begin on March 15 along the M4 highway from the settlement of Trumba – 2 kilometers 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 cease-fires 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.