"Four people have been killed, 11 have been wounded as a result of the explosion of a car bomb… in [the city of] Idlib," the source said.

Several buildings and vehicles sustained damage in the attack.  

Idlib and adjacent areas — the last major stronghold of militants in Syria — are home to an estimated 3 million civilians, more than half of whom have reportedly been displaced at least once during the ongoing six-year war.

Syria has been in a state of civil war since 2011, with the government forces fighting against numerous opposition groups and terrorist organizations. Russia along with Turkey and Iran are guarantors of the ceasefire regime in Syria.