RIO DE JANEIRO -- A band of suspected rogue policemen angry over an internal crackdown killed at least 29 people in a random shooting spree outside this city, authorities said Friday, raising fears among residents and rights groups of a revival of "death squads" in and around this violence-plagued metropolis.
The victims, five of them children, were gunned down Thursday night in two gritty northern Rio suburbs, sowing panic and chaos in the streets. Witnesses described the attacks as coming so fast and indiscriminately that bystanders had no time to flee or duck for cover.
The rampage shocked residents in a country already saddled with levels of violence some liken to war. It was Brazil's deadliest urban massacre since August 1993, when a death squad made up of disgruntled state police officers stormed into Rio's Vigario Geral slum and randomly shot to death 21 people.
Officials suspect the attackers may be policemen linked to a group of eight officers from a nearby precinct who were arrested this week in connection with two separate killings.
"The only thing I can say is that this crime will not go unpunished," Justice Minister Marcio Thomaz Bastos said, promising federal assistance in the investigation.
The secretary of public security for Rio de Janeiro state said he would send 250 police to back up dozens of locally based officers to help maintain security and stability in Baixada Fluminense, the poor, crime-ridden area where the killings occurred.
But that may not be enough to reassure residents deeply suspicious of the state police, which has a documented history of corruption and abuse.
Human rights groups renewed calls for the state to intensify efforts to clean up law enforcement to prevent a resurgence of extrajudicial death squads, which have been blamed for events such as the infamous Candelaria massacre of July 1993.
In that incident, eight homeless youths were gunned down in their sleep by policemen in the shadow of one of Rio's most important churches.
"Any hopes that such actions were horrors of the past have been dashed by the events of [Thursday] night, which show how far 'death squads' will go to spread terror and resist authorities' attempts to stop their activities," Amnesty International said.
The carnage began about 9 p.m. when a group of four to eight gunmen pulled up in one or two cars and opened fire on a crowded bar in the town of Nova Iguacu, according to authorities and local media reports. As patron after patron fell, the men started shooting at passersby.
On Friday, the death toll in Nova Iguacu stood at 19.
"People are afraid of going out. They were targeted," Lindberg Farias, the mayor of Nova Iguacu, said in a telephone interview. "It was a festival of terror."
From Nova Iguacu, the gunmen moved on to the neighboring town of Queimados for a second lightning attack, killing at least 10 more people.
"It was all very fast. They didn't stop," one witness told the Globo television network.
Among the dead were two young children and three teenagers. One of them, a 15-year-old boy, was shot as he played pinball at a game parlor.
The bullets provided a clue to authorities that police were probably involved in the massacre: The spent rounds came mostly from .40-caliber guns, the kind of firearms used by police, said Bastos, the justice minister.
Officials suspect that the gang was composed of rogue state cops from a nearby precinct who were angry over an internal investigation of their colleagues.
Eight officers were removed from duty this week and arrested for suspected involvement in the gruesome slaying of two Baixada Fluminense residents. The group of cops was reportedly caught on film tossing the severed head of one of the victims onto the precinct's patio.
"Those policemen were arrested and are being held because of strong evidence," said Mario da Silveira, a spokesman for the state public-security secretariat. "What is thought now is that officers linked to those bad cops might have committed" Thursday night's rampage.
Police brutality is a perennial problem in Brazil, the topic of countless reports by human rights groups and corresponding official pledges to tackle the issue. Activists say that government foot-dragging and Brazil's complex judicial system have prevented significant reform or clampdowns.
Mostly underpaid and undertrained, police officers are routinely accused of torturing suspects, coercing confessions and maltreating prisoners.
"Detainees in police stations, prisons and juvenile detention centers continued to be held in cruel, inhuman or degrading conditions" in 2003, Amnesty International said in June.
In September, a Rio tabloid published photos of special-unit officers forcing two young suspects to the floor during a raid on a shantytown, and later dragging off their bullet-riddled bodies. The pair died in a hospital. The head of the police unit was fired.