RIO DE JANEIRO, Brazil (AP) — Brazil’s President Luiz Inácio Lula da Silva said Wednesday he is sending the armed forces to boost security at some of the country’s most important airports, ports and international borders as part of a renewed effort to tackle organised crime in Latin America’s largest nation.

The decision comes days after members of a criminal gang set fire to dozens of buses in Rio de Janeiro, apparently in retaliation for the police slaying their leader’s nephew.

“We have reached a very serious situation,” Lula said at a news conference in Brasilia after signing the decree. “So we have made the decision to have the federal government participate actively, with all its potential, to help state governments, and Brazil itself, to get rid of organised crime.”

Brazil will mobilise 3,600 members of the army, navy and air force to increase patrols and monitor the international airports in Rio and Sao Paulo, as well as two maritime ports in Rio and Sao Paulo’s Santos port, the busiest in Latin America — and a major export hub for cocaine.

The deployment is part of a government’s broader plan that includes increasing the number of federal police forces in Rio, improving cooperation between law enforcement entities and boosting investment in state-of-the-art technology for intelligence gathering.

State and federal authorities have said in recent weeks they want to “suffocate” militias by going after their financial resources.

Rio’s public security problems go back decades, and any federal crackdown on organised crime needs to be supported by a far-reaching plan, the fruits of which might only be seen years from now, according to Rafael Alcadipani, a public security analyst and professor at the Getulio Vargas Foundation, a university in Sao Paulo.

“The federal government is being rushed into this due to previous lack of action,” said Alcadipani. “The government is trying, but the chance of this not working is huge … This is an emergency plan, something being done last minute as though it were a problem that arose just now, but it isn’t.”

Brazil’s Justice Minister Flávio Dino said the measures announced Wednesday are part of a plan being developed since Lula took office on January 1, and the result of months of consultations with police forces, local officials and public security experts.

The latest wave of unrest in Rio began October 5, when assassins killed three doctors in a beachside bar, mistaking one of them for a member of a militia. The city’s powerful militias emerged in the 1990s and were originally made up mainly of former police officers, firefighters and military men who wanted to combat lawlessness in their neighbourhoods. They charged residents for protection and other services, but more recently moved into drug trafficking themselves.

There has since been increased pressure for the state and federal governments in Brazil to come up with a plan and demonstrate they have a handle on public security in the postcard city.

On October 9, days after the doctors were killed, Rio state government deployed hundreds of police officers to three of the city’s sprawling, low-income neighbourhoods.

And on October 23, Rio’s police killed Matheus da Silva Rezende, known as Faustão, nephew of a militia’s leader and a member himself. In a clear show of defiance, criminals went about setting fire to at least 35 buses.

On Wednesday, federal police in Rio said it had arrested another militia leader and key militia members in Rio das Pedras and Barra da Tijuca, both in Rio state. They also seized several luxurious, bullet-resistant cars, a property and cash.