Clashes intensified between a jihadist group linked to al-Qaeda and rival rebels in northern Syria, as six rebel groups merged to confront new attacks by the jihadist group.
Militants of the Jabhat Fateh al-Sham, formerly known as al-Nusra Front, seized the Idlib Central Prison overnight following clashes with opposition rebel forces that were guarding the site, the Britain-based Syrian Observatory for Human Rights reports.
The attack comes as six rebel factions merged with Ahrar al-Sham, a conservative Sunni Islamist group, in north-western Syria, in response to the wide-scale assault by the jihadist group.
Suqour al-Sham, which was attacked by Fatah al-Sham earlier this week, was among the six rebel groups, according to a statement issued by Ahrar al-Sham.
It added that any attack on any member of the movement will be considered as a "declaration of war" that it would not hesitate to confront.
Clashes began as Fatah al-Sham launched an attack on Tuesday on posts of the Islamist Ahrar al-Sham in Idlib and the adjacent province of Aleppo, after it accused rebel groups, which took part in talks held in Astana this week, of conspiring against them.
The al-Qaeda-linked Fatah al-Sham have also accused some rebel groups like Suquor al-Sham of supplying information to the United States to strike their posts in Idlib.
Fatah al-Sham and the Islamic State extremist militia are excluded from the ceasefire in Syria.
Fatah al-Sham has lost several senior leaders in stepped-up US drone strikes over recent weeks.
