Brazilian presidential hopeful Aecio Neves on Sunday earned a key endorsement in his bid to defeat incumbent Dilma Rousseff -- from environmentalist candidate Marina Silva.

Neves, a Social Democrat, lost to Rousseff in the first round a week ago, but opinion polls now show him in a statistical dead heat with her ahead of the October 26 run-off -- making Silva's backing vital.

Brazilian authorities have arrested 16 military police on suspicion of extorting bribes from suspected drug traffickers and other offenses, authorities said Thursday.

The arrests stem from a raid carried out earlier this year in northern Rio in which two suspected drug traffickers were captured but later released.

Environmentalist Marina Silva, who emerged as a key power-broker after Brazil's first-round election, is leaning toward endorsing business favorite Aecio Neves for president, though it could provoke a rift with her party, reports said Tuesday.

Environmentalist Marina Silva, eliminated from Brazil's presidential election after placing third Sunday, did not reveal who she would endorse in the October 26 runoff.

Although most Brazilians say they want change after 12 years of rule by the Workers Party (PT) of incumbent Dilma Rousseff, the president topped the poll, going forward to a second round against Social Democrat Aecio Neves.

Brazilian presidential candidate Aecio Neves called on his rival Marina Silva's Socialist party to ally with his Social Democrats after defeating her Sunday to reach a run-off against incumbent Dilma Rousseff.

Brazil is deploying more than 400,000 security personnel, including 30,000 military, for Sunday's presidential and general elections, the country's Superior Electoral Court (TSE) said Saturday.

The TSE told broadcaster Globo it had authorized the deployment of troops in 254 municipalities in 11 of Brazil's 27 federal states, including Rio, scene of urban violence across the week which claimed at least five lives, and Amazonia.

Brazil's presidential election took another dramatic turn Saturday on the eve of the first-round vote as the final opinion poll showed popular environmentalist Marina Silva losing her second-place spot.

The early front-runner before slipping behind President Dilma Rousseff in recent weeks, Silva dropped to third behind Social Democrat Aecio Neves as both battle to face the incumbent in a likely run-off on October 26.

Despite economic woes and corruption, Brazilians appear ready to entrust incumbent Dilma Rousseff with the task of rebooting the world's seventh biggest economy in Sunday's presidential elections.

Latest polls out Thursday saw Rousseff stretching a double-digit first round lead over her main challenger, environmentalist Marina Silva, and winning a run-off by seven percentage points.

A large fire that roared through part of a Sao Paulo favela at dawn Wednesday killed one person and destroyed around 200 homes before being brought under control, firefighters said.

Hundreds of residents of the Sapopemba slum on the city's east side were affected by the large flames that engulfed dozens of wooden shacks as residents tried to escape with their belongings, Globo News TV showed.

An armed man who took an employee hostage at a hotel in the Brazilian capital and forced him to don a vest apparently stuffed with explosives has surrendered, authorities said Monday.

The gunman called a hotel courier in the early hours and pushed him into a room on the 13th floor of the Saint Peter hotel, a police spokesman told Agence France Presse.