SAO PAULO, Brazil — The official death toll from a wave of attacks here rose Tuesday to 133, including 18 inmates whose bodies were found after prison riots were finally quelled.
Calm returned to South America's most populous city, which was paralyzed by scores of attacks that began Friday. But concern grew over the possibility of excessive retribution by law enforcement officials when the number of suspects reported killed by the police almost doubled, from 38 to 71, in one day.
In a nation where the police have often been implicated in assassinations and extrajudicial killings, human rights advocates raised alarms and called for reform of an overcrowded prison system long known as a nest of organized crime abetted by corrupt officials.
The aftermath of the widespread violence -- blamed by authorities on a notorious prison gang ordering strikes from behind bars -- also seemed certain to affect Brazil's hotly contested national elections scheduled for October.
"The mood of terror we have had in the past few days, that civil-war like situation, cannot justify giving the police a license to kill," said Ariel de Castro Alves, coordinator of the National Movement for Human Rights.
Authorities insisted that officers had acted legally to counter the orchestrated attacks on police and fire stations, prisons, banks and other targets that also left at least 40 police officers and prison guards dead.
"We're at war with them, there will be more casualties, but we won't back down," Col. Elizeu Eclair Teixeira Borges, the state military police chief, told reporters.
Local media reported that the violence finally ceased after secret negotiations between the state government and the prison gang orchestrating the mayhem, the First Command of the Capital, known as PCC, its initials in Portuguese.
Authorities publicly denied negotiating with the gang, which, among other initiatives, is reportedly contemplating running candidates in local and national elections this year. But independent experts suggested that such talks were plausible, given the power and reach of the PCC, which has extensive cash holdings from drug and protection rackets.
Meanwhile, critics pointed to the government's slashing of aid for public safety reform in recent years and lack of attention to Brazil's notoriously brutal prisons, where revolts and takeovers are common.
"The question of public security is only addressed from crisis to crisis," said Denis Mizne, executive director of Instituto Sou da Paz, a group that studies justice issues in Sao Paulo.
Lawmakers quickly introduced legislation aimed at curbing the power of prison gangs. The state attorney general proposed enhanced penalties for inmates caught with cellphones, which are smuggled in and widely used by prison mob leaders to communicate with the outside world.
But critics said proposals for stiffer sentences and crackdowns on cellphone use would have little effect unless authorities acted to eliminate widespread corruption within the prison system. Many police officers and guards, paid low wages, are suspected of being on gang payrolls.
"We also need to combat corruption within the prison system itself, and implement internal systems of control," said Julita Lemgruber, a former penitentiary director in Rio de Janeiro who now heads a prison reform group. "Brazil's problem isn't a lack of laws -- it is the lack of implementation and enforcement."
The uproar took on a political flavor as President Luiz Inacio Lula da Silva and his chief electoral rival, former Sao Paulo Gov. Geraldo Alckmin, sought to deflect blame.
Analysts predicted that each side would try to use the issue of violence to its advantage. The president's supporters probably will point out the rise of the PCC gang during Alckmin's term as governor, while the ex-governor will emphasize the alleged failure of federal government to respond to the problem of crime and prisons.
"The question of public security is now going to be the central theme of the election," said Silvia Ramos, who heads a study center at Candido Mendes University in Rio de Janeiro. "The attacks have ... revealed the incapacity of the state to respond -- their responses have been insufficient, and the PCC has demonstrated a great degree of control."
Paradoxically, the debate is heating up at a time when murder rates have been dropping in Sao Paulo, in large part because of improved policing, authorities say.
Sao Paulo's public transportation system, paralyzed Monday by the deliberate burning of dozens of buses, returned to near-full strength Tuesday.
All 80 jails and prisons where inmates revolted were back in government control Tuesday, and hundreds of hostages had been released, authorities said.
The great majority of shops here reopened and most students returned to school, though traffic was relatively light and some residents clearly decided to remain at home.
Special correspondent Soares reported from Sao Paulo and Times staff writer McDonnell from Buenos Aires. Special correspondent Suzy Khimm in Rio de Janeiro and Andres D'Alessandro of The Times' Buenos Aires Bureau contributed to this report.