Islamic State (IS) inmates staged a riot inside a prison run by the Kurdish forces in Syria's Hasakah province, a war monitor reported.
In the riot that broke out after Wednesday midnight, IS inmates destroyed a wall in Ghweiran prison and reached the yard of the facility, demanding permission for family visits and fair trials, Xinhua news agency quoted the UK-based Syrian Observatory for Human Rights as saying.
The Syrian Democratic Forces (SDF) and the Kurdish security forces laid siege to the prison while warplanes of the US-led coalition hovered over the prison, the watchdog added.
It is the second such riot in the Ghweiran prison since July.
On July 30, 16 IS inmates staged a riot in the prison and were shot dead by the Kurdish security forces.
The Observatory said the Ghweiran prison houses thousands of foreign IS members detained by the SDF.
The SDF runs prisons in areas it controls in northeastern Syria, where around 10,000 IS members are imprisoned, 2,000 of whom are foreigners.