LANSING, Kan. (AP) — Dozens of inmates at the Lansing Correctional Facility in Kansas rampaged through offices, breaking windows and setting small fires for several hours before the facility was secured, a prison official said Friday.

All inmates were secured and accounted for by about 1 a.m. Friday, Bowman said in an email cited by NBC News. Bowman did not immediately return a message left Friday morning by The Associated Press seeking an update.

After the rampage, two inmates were treated for minor injuries, according to a Kansas Corrections PIO.

“Investigation is underway to determine who and how many involved and then appropriate response for each. That will likely take days if not longer,”a Kansas Corrections PIO said. “They damaged lots of property like cameras, windows, fire extinguishers [and] offices.”

The disturbance began about 3 p.m. Thursday in medium-security cell house C, said Randy Bowman, spokesman for the Kansas Department of Corrections. By 9 p.m., some inmates had given up or gone back to their cells.

Bowman said the disturbance started when some inmates refused to return to their cells as ordered. He said it appeared about 50 inmates were involved at first, with between 20 or 30 participating through the evening.

It’s unclear what started the riot, Bowman said.

The Lansing prison has drawn attention recently amid the coronavirus crisis, with the corrections department reporting 14 staff and 12 inmates with confirmed cases of COVID-19 at the facility.

On Thursday, the American Civil Liberties Union of Kansas asked the Kansas Supreme Court to immediately release prisoners who have preexisting medical conditions that make them vulnerable to the coronavirus. That class action petition is on behalf of seven inmates at prisons including the Lansing facility.

The department said Thursday that state officials recognize that inmates and prison staff are especially at risk of infection and have taken steps to reduce the impact of COVID-19 in corrections facilities.