Syria’s transitional authorities arrested a former commander in a major security operation on Thursday after a deadly ambush by forces that previously fought for ousted President Bashar al-Assad, elevating concerns of sectarian violence in the country. 

What happened: The UK-based Syrian Observatory for Human Rights reported that the Military Operations Directorate conducted a "large-scale security campaign” on Thursday in parts of the Tartous countryside, including Khirbet al-Ma’zah. Maj. Gen. Mohammad Kanjo Al-Hassan, described as a former judicial official in Assad’s security apparatus who served at the notorious Sednaya prison, was arrested along with 20 of his affiliates. The arrests followed a large sweep of the area conducted by security forces, which included searching people's homes, according to the war monitor.

The security operation followed clashes in Khirbet al-Ma'zah on Wednesday between forces that previously fought for Assad and the transitional security forces led by former rebel group Hayat Tahrir al-Sham (HTS).

Syria’s official news agency, SANA, reported that 14 members of the security forces were killed and 10 others were injured, describing the incident as a “treacherous ambush.”