Eleven Syrian soldiers were killed in the northwest part of the country during separate attacks carried out by the Hayat Tahrir al-Sham jihadist group — known as HTS — on Wednesday, a war monitor reported.
"HTS fired shells and rockets at a Syrian military post, killing eight soldiers near Kafr Ruma in Idlib province," said the Britain-based Syrian Observatory for Human Rights.
The monitor later reported that "three Syrian soldiers were killed by sniper fire" near Kafr Nabl in the same province, adding that HTS jihadists also were responsible.
HTS is headed by ex-members of Syria's former al-Qaida franchise.
Syrian state media did not immediately report either attack.
About half of the northwestern province of Idlib and areas bordering the neighboring provinces of Aleppo, Hama and Latakia are dominated by HTS and other rebel factions.
The Idlib region is home to about 3 million people, about half of whom are displaced.
Observatory head Rami Abdel Rahman told Agence France-Presse that since the end of 2022, the jihadists "have intensified operations against regime forces in Idlib ... in the context of a rapprochement between Ankara and Damascus."
He said exchanges of fire and clashes between regime forces and jihadist factions had killed more than 60 people since the start of the year, most of them pro-regime forces. One of the jihadists killed was a French national.
Ankara became a sworn enemy of Damascus when it began backing rebel efforts to topple the regime of Syrian President Bashar al-Assad at the start of the civil war.
But in late December the defense ministers of Turkey and Syria held landmark negotiations in Moscow — the first such meeting since 2011.
The disputed reconciliation has alarmed Syrian opposition leaders and supporters who reside mostly in parts of the war-torn country under Ankara's indirect control.
Assad said in January that a Moscow-brokered rapprochement with Turkey should aim for "the end of occupation" by Ankara of parts of Syria.
Turkey has military bases in northern Syria and backs some local groups fighting the regime and against Syrian Kurdish forces that it considers "terrorist" groups.
Ankara has never publicly backed hardline group HTS but is believed to coordinate with its forces.
HTS, which is sanctioned by the United Nations as a terrorist organization, formally broke ties with al-Qaida in 2016 and incorporated several smaller Syrian rebel factions in a major re-branding effort.
Widely seen as the strongest and best organized of Syria's rebel groups, it has presented itself as the mainstay of Syria's opposition.
With Russian and Iranian support, Damascus has clawed back much of the ground lost in the early stages of Syria's conflict, which erupted in 2011 when Assad's government brutally repressed pro-democracy protests.
The war has killed nearly half a million people since it broke out, displacing almost half of Syria's pre-war population.
Despite periodic clashes, a cease-fire reached in 2020 by Moscow and Turkey has largely held in the northwest.