GEO Group-Managed Prison in Indiana Struck by Riot

A "full-scale riot" broke out today at a medium-security men's prison, according to the mayor, and pictures taken from television helicopters showed at least two fires burning in the courtyard.

The medium-security facility is managed by the GEO Group , based in Boca Raton, Fla. Shares of GEO fell more than 1% after CNBC Senior Correspondent Scott Cohn reported on the riot.

Indiana Department of Correction spokeswoman Java Ahmed confirmed there was a disturbance at the New Castle Correctional Facility, about 43 miles east of Indianapolis. She had no details.

New Castle Mayor Tom Nipp said the entire city police force had been activated.

The prison, built in 2002, houses about 450 inmates.