111 Inmates Die in Brazil Prison Riot : Latin America: Authorities say most died at hands of other convicts in overcrowded facility. Thirty-four troops hurt.

A gang fight between inmates in Latin America’s largest prison has left 111 prisoners dead and injured 34 riot troops sent in to put down the uprising at the overcrowded facility, officials said Saturday.

Officials said it appeared that most of the prisoners died at the hands of other inmates in the melee Friday. They said the violence may have been planned as part of a mass escape, but there were no immediate reports that any prisoners slipped out.

The fight began Friday afternoon when a brawl erupted between rival groups in an outdoor recreation area of Carandiru Prison, officials said.

The prison, which holds 7,500 inmates but is built to hold 4,000, has long been criticized by human rights groups.

The melee spread quickly to prison cells in Pavilion 9, where inmates grabbed pipes and homemade knives, and seized 10 pistols from guards, Pedro Franco de Campo, Sao Paulo state security director, told a news conference Saturday afternoon. The inmates set mattresses, beds and blankets on fire, he said.

De Campo said that 300 riot troops were sent in 2 1/2 hours after the fight began and that they put down the uprising an hour later.

The prison, in Sao Paulo’s working-class northern district, was in a lock-down Friday, with all inmates kept in their cells, De Campo said. A guard said Saturday that security was eased and families were allowed to visit some prisoners.

It was not yet clear how the inmates died. De Campo said there were indications that mostly the rioters killed each other.

“It was not a police massacre,” he said in a live TV interview. “Most of the deaths were caused by the inmates themselves.”

“There are indications that a mass prison escape was planned,” he added, suggesting that the inmates were trying to take advantage of city elections held Saturday.

“The prisoners thought it would be easier to escape on the eve of the national city elections with all of the police in the streets to keep order,” he said.

A report by the New York-based human rights group Americas Watch has described Brazil’s prisons as “hell holes” in which inmates are treated “worse than cattle.”