One of Brazil’s most powerful organised crime gangs set off riots in 36 prisons and launched attacks on police that left 52 people dead and 53 wounded over the weekend, increasing fears over security in São Paulo, the country’s largest state.

The trouble flared after state penitentiary officials transferred hundreds of leaders of the Primeiro Comando da Capital (PCC) already in custody to a new high-security complex late last week. Authorities said they were trying to head off a multi-prison revolt planned for the weekend.

Gang members then launched at least 100 separate attacks against police posts that began on Friday night and continued until Sunday, in what has been one of the state’s bloodiest weekends.

Order had been restored to about 17 of the prisons by Sunday afternoon.

Analysts believe the attacks on police will continue. “For the violence to end, it will be necessary to eliminate the misery that causes crime. Police repression will only prompt more violence,” said Anselmo Neves Maya, an attorney who represents many members of the PCC.

In an attempt to keep the violence from spilling over into the centre of São Paulo, police set up roadblocks on arterial roads.

President Luiz Inácio Lula da Silva blamed the violence on a lack of investment in education.

The attacks came days after São Paulo announced a 54 per cent decline in its homicide rate over the past seven years. 

In the same period, the state’s prison population has ballooned by nearly 70 per cent.

Crime is expected to be a campaign issue in Brazil’s presidential elections later this year.

The decline in violent crime had been expected to be a major plank in the campaign efforts of Geraldo Alckmin, who recently resigned as governor of São Paulo state to run for president.

The PCC first hit the headlines in February 2001, when it orchestrated a simultaneous revolt in 29 prisons in São Paulo state, leaving 19 dead.