CNN  — 

Several Islamic State in Iraq and Syria (ISIS) members escaped from a Syrian prison on Sunday by ripping off doors and using them to break down a wall during a “detention facility uprising,” authorities said.

The Ghweran prison, located in the northeastern city of Hasakah, is run by the Kurdish Syrian Democratic Forces (SDF), a key US partner in the fight against ISIS.

ISIS prisoners took over the first floor floor of the prison, tore down some of the internal walls, and destroyed the doors, Mustafa Bali, head of the SDF press office, said in a tweet Sunday.

“Some of them managed to escape and the search for them is ongoing,” he added.

Inside, prisoners staged a riot that authorities struggled to control. “The situation is tense inside the prison currently ” Bali said. “The anti-terrorist forces are dealing with the situation to restore control of the ground floor in the prison and restore calm to the prison in general.”

A US military official confirmed to CNN Sunday that there was an ongoing situation at the prison. CNN reporters on the ground could hear loud chanting from prisoners inside.

The identities of the ISIS members who escaped, and how many of them did, is not yet clear.

The US-led military coalition fighting ISIS is providing aerial surveillance assistance in an attempt to find them, the coalition said in a statement.

“The SDF is quelling the insurrection. The Hasakah facility holds low-level ISIS members. The Coalition does not staff any detention facilities or camps in Syria,” said the statement.

The SDF is responsible for all ISIS prisons in northern Syria. These camps and prisons hold some 11,000 to 12,000 ISIS fighters captured on the battlefield, as well as those displaced by the fight against ISIS.