Riots break-out at Syria jail holding suspected IS members
A senior member of the Syrian Democratic Forces (SDF) running Ghouiran prison in the northeast Syria city of Hassakeh acknowledged that an uprising had taken place.
The official, who asked to remain anonymous, told AFP that Islamic State members in the prison had revolted.
"Some of them managed to get out into the prison courtyard," the source added.
"Security forces are on high alert. International coalition planes are flying over the prison and the region."
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Coalition military spokesman Colonel Myles Caggins III said: "The Coalition is assisting our Syrian Democratic Forces partners with aerial surveillance as they quell an insurrection" at the prison.
But only low-level prisoners were kept at the jail, he added.
The London-based Observatory, which has an extensive network of contacts inside Syria, said at least four people had escaped from the prison.
Members of the Islamic State had led the uprising and a search has started for those who had escaped, it added.
SDF spokesman Mustafa Bali, posting on Twitter, said prisoners had broken walls and torn off internal doors.
"The situation is still tense inside the prison," he said, adding that reinforcements were on the way to try to regain control.
A year after having declared victory against the Islamic State in Syria, Kurdish forces are still holding around 12,000 IS fighters in the northeast of the country, according to their own figures.
They include Syrians, Iraqis and between 2,500 and 3,000 foreign nationals from some 50 countries.
While they have called on those countries to take back their nationals, they are also resigned to the prospect of putting them on trial, given the reluctance of several western governments have their nationals repatriated.
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