Elite federal troops are on standby to patrol the streets of Rio de Janeiro and the state’s borders as the authorities try to clamp down on gang violence before next month’s Carnival.

Gang attacks last week left 19 people dead and the authorities fear that renewed violence could keep tourists away.

Federal and state officials agreed last night to deploy the elite troops after a request from Rio’s newly elected governor, Sérgio Cabral. Mr Cabral said that the 7,700-strong National Security Force, a paramilitary unit created in 2004, would help to police the state’s border as a first step. He said that the move was intended to stop the flow of criminals, drugs and arms into the state.

Mr Cabral made a crackdown on violence a key part of his election campaign. Rio is one of the world’s most violent cities and President Luiz Inácio Lula da Silva says that the federal Government is ready to help Rio to defeat the “terrorism”.

The violence started on December 28 with attacks on police stations and buses. In one incident an interstate bus with 28 people on board was stopped and firebombed. Eight died. The attacks are believed to have been ordered from inside Rio’s jails by gang leaders who fear that the governor of the state will introduce a harsher penal regime. Until now criminals have been able to run their business from within jail with little interference.

In May criminals in São Paulo attacked police in response to plans by the authorities to subject their jailed leaders to stricter discipline. The violence left more than 200 dead.

President Lula da Silva has proposed new legislation to tackle gang violence but legal experts say that the problem is the failure of the security forces to implement existing laws. Rio’s police are regarded as violent and corrupt.

The city is the centre of a massive cocaine industry based in the shantytowns, or favelas. The drug was introduced into the city in the 1970s by traffickers. Local criminals began dealing cocaine from the favelas and a huge market quickly sprang up.This strengthened violent criminal groups such as the Comando Vermelho (Red Command), which controls many of the favelas, turning them into virtual no-go zones for police.

The army was sent into the hills above Rio in March after gangs were accused of stealing arms from a military depot.

Before the recent wave of attacks President Lula da Silva and Mr Cabral pledged to intensify efforts to curtail the gangs and prevent them from disrupting this year’s Pan American Games, which will be held in the city in July.

The games are seen as an important advertisement for Rio’s and Brazil’s ability to organise big international events — an important precursor to Rio’s proposed bids for the Fifa World Cup and the summer Olympics.

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