More than 100 people have now been killed in a bombing campaign by President Assad and his allies, targeting the last major rebel-held area.
Eight months ago, the Russians and Turks agreed a ceasefire in Idlib with their troops monitoring a buffer zone around the province. The Syrian government and jihadist rebels blame each other for breaking the truce.
The Syrian army has now launched a ground offensive inside the buffer zone. At least 12 medical centres have been hit and more than 150,000 civilians have fled the fighting.