Turkey sent reinforcements to the last rebel-held enclave in northwestern Syria as Russia stepped up air strikes there on Sunday, several sources said, three days before leaders Vladimir Putin and Tayyip Erdogan are due to meet for talks.
Residents as well as opposition and military sources said that Russian jets bombed villages around the city of Afrin on Sunday, intensifying air strikes on towns and villages held by Turkish-backed rebels which have escalated in the last week.
Rebel sources said at least five fighters from a Turkey-backed faction were killed while at least 12 civilians were injured when Russian jets flying at high altitudes dropped ordnance, according to a network of plane spotters who document sightings of jet fighters.
The Russian bombing campaign has spread from Jabal al Zawya in Idlib province further northwest to the Afrin area near the Turkish border, with shelling from Syrian army outposts aided by Iranian-backed militias.