One person has been injured in a terrorist attack in Azaz district in northern Syria, security sources said late Sunday.

Syrian National Army (SNA) vehicle was bombed, said the sources, who asked not to be named due to security concerns.

No one has claimed responsibility for the attack, but officials in the region think it was carried out by the YPG/PKK terrorist group.

The terrorist organization, which continues to attack Syria's Tal Rifaat and Manbij regions, often targets the cities of Jarablus, Azaz and Afrin.

Syrian opposition forces control Azaz, which falls near the Turkish border.

Azaz was liberated from Daesh terrorists by the Turkish military and aligned Syrian opposition forces in the 2016 Operation Euphrates Shield. Since then, the town has become an area with a high concentration of refugees and the main hub of Turkish relief efforts.

In the last three years, Turkey's Euphrates Shield, Olive Branch and Peace Spring operations liberated the northern Syrian region from YPG and Daesh terrorists, allowing hundreds of thousands of displaced civilians to return to their homes.

However, a number of liberated cities – including al-Bab, Jarablus, Azaz, Afrin, Tal Abyad and Ras al-Ayn – remain subject to sporadic terrorist attacks by the YPG.

In its more than 30-year terror campaign against Turkey, the PKK-listed as a terrorist organization by Turkey, the U.S. and European Union-has been responsible for the deaths of 40,000 people, including women, children and infants. The YPG is the PKK's Syrian offshoot.