Kurdish-led security forces said they restored calm Monday (March 30th) at a prison in north-east Syria after a riot by "Islamic State of Iraq and Syria" (ISIS) inmates.

Four detainees believed to have broken out of Ghouairan prison in the town of al-Hasakeh had been tracked down within the jail, the Syrian Observatory for Human Rights said.

Some 5,000 ISIS suspects are held in the jail run by the Kurdish-led Syrian Democratic Forces (SDF), according to the Observatory.

On Sunday, prisoners managed to dismantle cell doors and pierce through dormitory walls, overrunning the jail's ground floor, the SDF said.

"The situation in the prison is totally back under control," the SDF said Monday in a statement.

The rapid intervention forces of the SDF had "intervened directly, ending the riot and securing" the facility, it said.

The statement said "no escape had occurred", refuting earlier reports.

Aircraft from the US-led coalition against ISIS assisted in searches overnight and into Monday morning, coalition spokesman Col. Myles Caggins said.

Only low-level prisoners were kept at the jail, he added.

ISIS overran large parts of Syria and neighbouring Iraq in 2014, imposing its brutal rule over millions.

But various military offensives slowly whittled down the group's proto-state, wiping it out a year ago.

Syria's Kurds hold some 12,000 suspected extremists in several prisons across the north-east of the country.

They are mostly Syrians and Iraqis but also 2,500 to 3,000 foreign fighters from dozens of other countries.

Kurdish authorities called for foreign countries to repatriate their nationals accused of belonging to ISIS, but these have been largely reluctant.

Instead the Kurds are now urging the international community to help better secure their jails and organise trials of ISIS-linked detainees on their own soil.

Despite the end of their territorial control, ISIS fighters still maintain a presence in SDF-held areas and continue to claim frequent attacks.