Turkey and Russia agreed in September last year to turn Idlib into a de-escalation zone in which acts of aggression are expressly prohibited.
Since then, more than 1,300 civilians have been killed in attacks by the regime and Russian forces in the de-escalation zone as the cease-fire continues to be violated.
Over a million Syrians have moved near the Turkish border due to the intense attacks this year.
According to the National Coalition for Syrian Revolutionary and Opposition Forces, Idlib province is home to around three million civilians, 75% of them women and children.