Syrian troops on Friday reclaimed a cluster of towns they had lost early in the eight-year-old war, pressing their offensive in the northwest, the country’s last big rebel stronghold.
The army drove out the last rebel fighters from the Hama countryside - the latest in a string of crushing blows across Syria - and advanced on a Turkish military post there.
Government forces have pounded the south of Idlib province and nearby Hama from the air and the ground this week, prompting a new civilian exodus. Hundreds of people have been killed in the campaign since late April, the United Nations says.
Rebel officials did not respond to requests for comment.
President Bashar al-Assad turned towards Idlib after shoring up his rule in most of Syria with Russian and Iranian help.
Still, the prospect of more advances in parts of Syria that remain outside his control is obstructed: in the northwest by Turkey’s interests near its border, and in the northeast by the presence of U.S. forces alongside Kurdish fighters.
Ankara backs rebel forces that control swathes of territory north of Idlib under its sphere of influence, and some that have a presence in Idlib.
Turkish President Tayyip Erdogan told his Russian counterpart Vladimir Putin on Friday that Syrian army attacks were causing a humanitarian crisis and threatening Turkey’s national security.
In a phone call, Erdogan said the attacks violated a ceasefire in Idlib and damaged efforts for a solution in Syria, the Turkish presidency said.
The latest army gains have put Turkish troops in Idlib in the firing line and threaten Ankara’s hopes of preventing a new wave of refugees on its border.