ANKARA 

Turkish and Russian troops carried out their 17th joint patrol along the key M4 highway in Syria's northwestern province of Idlib, Turkey's National Defense Ministry said Tuesday.

"To maintain the Turco-Russian ceasefire agreement in Syria, the 17th Combined Land Patrol was conducted in Idlib province Tuesday," the ministry said on Twitter.

"Due to a detonation of an unidentified explosive, a patrol vehicle was lightly damaged and taken to a safe location," it added, noting that no personnel had been harmed in the incident.

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

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 mi) 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.