SAO PAULO -- A notorious criminal gang unleashed a second wave of attacks against police yesterday, bringing to at least 52 the number of people killed in what one official said was the deadliest assault of its kind in Brazil's history.
Meanwhile, another 33 related prison rebellions broke out yesterday, bringing the number of penitentiary revolts across Sao Paulo state to 51 at the peak of the two-day uprising -- more than one-third of Brazil's 144 prisons. By late yesterday, rebellions continued at 41 prisons, and inmates were holding 229 prison guards hostage.
The inmates have not made any demands nor have they harmed any of their hostages, said Jorge de Souza, a spokesman for the Sao Paulo Prison Affairs Department.
He said visiting relatives were inside several of the prisons but ''we don't consider them hostages because they are there to show solidarity with their jailed relatives."
Enio Lucciola, a spokesman for the Sao Paulo State Public Safety Department, said the attacks and prison rebellions, planned by the First Capital Command, known by its Portuguese initials, PCC, ''were the most vicious and deadliest attacks on public security forces that have ever taken place in Brazil."
The attacks were in response to the transfer of eight imprisoned PCC leaders, a practice authorities use to sever prisoners' ties to gang members outside prison.
Lucciola said authorities were prepared for some kind of PCC attack after the transfer ''but we never imagined it would be so big or ferocious."
Late last evening, the Folha de Sao Paulo newspaper's website reported that the death toll had risen to 55, and that at least 10 public buses had been burned by bandits in the city of Sao Paulo. Television images showed the buses engulfed in flames, while Folha Online said passengers were ordered out of the vehicles before bandits set them ablaze.
The Sao Paulo state government said the PCC carried out at least 100 attacks on Friday, Saturday, and yesterday that killed at least 35 police officers, the girlfriend of one of them, and two passers-by. Fourteen suspected gang members were killed in gun battles with police.
At least 72 people were arrested, ''all of them with long criminal records," Lucciola said.
Officers set up checkpoints to search vehicles, and barriers were placed in front of many police stations to block pedestrians and vehicles. TV footage showed bullet-riddled police cars and shattered glass at one station.
Assailants also attacked patrol cars, bars popular with off-duty police officers, a courthouse, and a police outpost on the outskirts of the city of Sao Paulo.
Police were notably absent yesterday morning from Avenida Paulista, one of Sao Paulo's most important thoroughfares.
''To tell you the truth, I prefer it that way," said Cristiane Teixeira, a 30-year-old newsstand employee. ''After what I read in the newspaper, I don't think it's very safe to be near a policeman, because you may end up getting shot by people wanting to kill him."