At least nine inmates have died in Georgian prisons in the past 10 days as the Caucasus Mountains nation suffers through high temperatures not seen in two decades, officials and rights activists said Thursday.

Rights groups say 10 inmates have died of heat-related illness in penal institutions as temperatures have soared to 113 degrees. On Thursday, temperatures in the capital of Tbilisi topped out at 102 degrees.

Deputy Justice Minister Givi Mikanadze said nine inmates had died since the heat wave in Georgia began Aug. 1. He denied, however, that the deaths were heat-related, saying the inmates were all middle-aged and had suffered apparent heart attacks.

He said medical teams are monitoring the prisoners around the clock. "Prisoners have plenty of water, fans," he said.

Georgian prisons are overcrowded and poorly ventilated, and older inmates were suffering more than others, said Nana Kakabadze, a former political prisoner and rights defender.

Weather forecasters say the ex-Soviet republic has not seen temperatures as high as this summer's in more than 20 years.