A total 506 inmates were killed and more than 600 wounded in staggering levels of violence in Venezuelan jails in 2013, a report released Wednesday said.
Still, the violence behind bars marked a decrease from 2012 -- 14 percent fewer killings and 46 percent fewer injuries, the NGO Venezuelan Prisons Monitor said.
"The woundings and killings generally involve fire arms and blunt instruments," the report found, noting that the average age of victims was 28.
Venezuela's 51 prisons are extremely overcrowded as the South American nation struggles with surging violent crime.
Venezuela has one of the world's highest murder rates, with 79 murders per 100,000 inhabitants last year, according to the non-profit Venezuelan Violence Monitor.
The interior ministry, however, has a lower murder rate of 39 homicides per 100,000.
Experts say that the low success rate in prosecuting violent crimes is the main cause of the crisis. About 92 percent of murders go unsolved.