Prisoners and authorities say some inmates of Greece's only penitentiary hospital have gone on a rampage, smashing parts of the facility's ground floor.

Local media said the rioting began Friday morning after a visitor was detained for allegedly attempting to smuggle drugs. The hospital is part of the Korydallos penitentiary complex, the nation's largest.

Several hospital inmates told The Associated Press that Georgian prisoners damaged the hospital's pharmacy and a guards' station, and that riot police had arrived, but had not yet taken any action. They spoke on condition of anonymity because they were using an unauthorized telephone.

Hospital inmates have held hunger strikes in recent months, demanding better conditions. The European Court of Human Rights has repeatedly ruled that conditions in several Greek prisons constitute inhuman or degrading punishment.