Death toll is highest since announcement of de-militarised zone in September
Syrian government forces killed 22 rebels overnight near Idlib province, in the deadliest such attack in an area where a recent truce is to be enforced, a monitor said Friday.
Fighting erupted when government troops seized a position in a rural area in the north of neighbouring Hama province that had been held by the Jaish al-Izza group, the Syrian Observatory for Human Rights said.
Idlib and some surrounding areas are the last major rebel bastion in Syria, where the Russian-backed government has in recent months retaken much of the territory it had lost since the civil war erupted in 2011.
It had threatened an assault on rebel territory, home to around three million people, but a deal for a de-militarised buffer zone around it was reached in September between Moscow and rebel backer Ankara.
Several deadly skirmishes have occurred since the deal but 22 is the highest number of known fatalities in a single incident inside the planned buffer zone, the Observatory said.
"This is the highest death toll in the de-militarised zone since it was announced," Rami Abdel Rahman, head of the Britain-based monitoring group, told AFP.
The deaths come less than a week after a four-nation meeting in Istanbul seeking a solution to the crisis in Idlib.
Following the meeting on Saturday, leaders of Turkey, Russia, France and Germany called for a political solution to Syria's devastating seven-year civil war and a lasting ceasefire in Idlib.
A joint statement adopted at the end of a major summit in Istanbul on Saturday said the countries were committed to working "together in order to create conditions for peace and stability in Syria".
It also "stressed the importance of a lasting ceasefire" in Idlib, while hailing "progress" following a deal last month between Syrian-government supporter Russia and rebel-backer Turkey to create a buffer zone around the northwestern province.
Turkish President Recep Tayyip Erdogan spoke for several hours with Russia's Vladimir Putin, France's Emmanuel Macron and German Chancellor Angela Merkel about the Syrian conflict, in which more than 360,000 people have been killed since 2011.
The joint statement, read by Erdogan, called for a committee to be established to draft Syria's post-war constitution before the end of the year, "paving the way for free and fair elections" in the war-torn country.
It also said there was "the need to ensure humanitarian organisations' rapid, safe and unhindered access throughout Syria and immediate humanitarian assistance to reach all people in need," the AFP news agency reported.