Eleven Syrian soldiers were killed in the country's north-western Idlib province in attacks carried out by the Hayat Tahrir Al Sham extremist group, a war monitor has reported.
The group fired "shells and rockets at a Syrian military post" near the town of Kafr Ruma on Wednesday, killing eight troops, the UK-based Syrian Observatory for Human Rights said.
Three Syrian soldiers were killed by Hayat Tahrir sniper fire near Kafr Nabl, about 7.5km west, the monitor said.
The militant group is led by former members of Jabhat Al Nusra, which was linked to Al Qaeda.
Syrian state media did not immediately report either attack.
Large parts of Idlib and areas near the neighbouring provinces of Aleppo, Hama and Latakia are dominated by militant groups, including Hayat Tahrir.
Idlib province is home to about three million people. About half of them are displaced.
Rami Abdulrahman, head of the war monitor, told AFP that since the end of 2022, extremists "have intensified operations against regime forces in Idlib ... in the context of a rapprochement between Ankara and Damascus".
Gunfights and clashes between regime forces and extremist groups have killed more than 60 people since the start of the year, most of them members of forces supporting the regime, he said.
One of the militants killed was a French citizen.
Ankara backed rebel efforts to topple the regime of Syrian President Bashar Al Assad at the start of the civil war in 2011.
But in December last year, the defence ministers of Turkey and Syria held talks in Moscow – the first such meeting since 2011.
The prospect of the countries repairing ties has alarmed Syrian opposition leaders and supporters who live in parts of the country under Turkish control.
Mr Al Assad said in January that a Moscow-brokered rapprochement with Turkey should aim to secure "the end of occupation" by Ankara in Syria.
Turkey has military bases in northern Syria and backs some groups fighting against the regime and Syrian-Kurdish forces that Ankara considers to be terrorist groups.
Ankara has never publicly backed Hayat Tahrir.
Hayat Tahrir, which has been designated as a terrorist organisation by the UN, formally severed ties with Al Qaeda in 2016 and incorporated several smaller Syrian rebel factions.