Militants from the self-styled "Islamic State" group attacked a Kurdish-run jail in Syria's al-Hasaka in an attempt to free jihadists associated with the group, the Kurdish-led Syrian Democratic Forces (SDF) said in a statement.
While the UK-based Syrian Observatory for Human Rights said "a number of prisoners managed to escape," the SDF did not mention any prisoners fleeing.
The US-backed SDF said IS "sleeper cells ... infiltrated from the surrounding neighborhoods and clashed with the internal security forces."
Led by the Kurdish YPG militia, the SDF said the escape attempt was thwarted. The incident coincided with a car bomb hitting the entrance of the Ghwayran prison, which is one of the largest facilities holding IS fighters in the semi-autonomous region controlled by Kurdish authorities in northeast Syria.
There were some unconfirmed reports of inmates being killed in the mutiny that arose ahead of the attack, the latest in a string of attempts to flee SDF jails.
Kurdish-run jails and IS detainees
According to Kurdish authorities that run the prison, more than 50 nationalities are represented across such prisons that house more than 12,000 IS suspects. Their countries of origin range from France to Tunisia, where authorities are reluctant to take them back over fears of a public backlash.
However, relatives of some detainees say inmates include young children and others that were arrested on flimsy charges or for disobeying the SDF's policy of conscription.
The Islamic State group once held vast parts of Syria and Iraq but lost most ground after a long military altercation with Kurdish forces from both countries, who were backed by the United States and other powers. This included some training and other non-combat support from the German military, but only in Iraqi Kurdistan, not in Syria.
Remnants of the IS network were pushed back to their desert hideouts, which they now use to harass the Syrian government and allied forces.
see/msh (Reuters, AFP)