The UN says there has been an alarming rise in civilian casualties in Syria's last opposition-controlled province.
It says 90 civilians, half of them children, were killed in March.
The bombardment of Idlib by the Syrian government has intensified, despite a ceasefire.
The opposition blames the government and says it has been targeting residential neighbourhoods and markets.
Moscow is one of the government’s main backers - and says it is helping it eliminate what it calls "a terrorist threat" in the province.
Al Jazeera's Zeina Khodr reports from Beirut.
