Brazil's central bank said Wednesday it would ease banks' reserve requirements for the second time in less than a month, freeing up $4.5 billion to stimulate lending and boost the sluggish economy.

Under the new rules, banks will be allowed to use up to 60 percent of reserves for credit operations, an increase from the 50-percent limit announced on July 25.

Environmentalist Marina Silva could unseat incumbent Dilma Rousseff in Brazil's presidential elections in October, a poll found Monday, reflecting an altered political landscape since Silva's running mate was killed in a plane crash.

Silva, a 56-year-old former environment minister, has moved into second place ahead of the October 5 first-round vote and would defeat Rousseff in an October 26 runoff, the poll by Datafolha found.

The death in a plane crash of Socialist Party candidate Eduardo Campos has put an unpredictable spin on Brazil's presidential elections, opening the way for a popular environmentalist to challenge incumbent Dilma Rousseff.

The top two candidates, Rousseff and Social Democrat Aecio Neves, halted their campaigns as Brazil began a three-day period of national mourning for Campos, a 49-year-old former governor who had been running third in opinion polls when his jet crashed Wednesday en route to Sao Paulo.

Brazilian presidential candidate Eduardo Campos, a contender to unseat President Dilma Rousseff in October elections, died Wednesday when his campaign jet crashed in the city of Santos, killing all seven people aboard.

Campos, a 49-year-old socialist who had been running third in the polls, was flying to Sao Paulo to record a TV segment when his Cessna 560XL slammed into a gymnasium and several houses, breaking into pieces and igniting a large fire.

Police in Brazil dismantled a well-armed gang accused of extorting, torturing and killing poor residents of Rio de Janeiro, state security authorities said Thursday.

Japan's Prime Minister Shinzo Abe on Friday left on a five-nation tour of Latin America and the Caribbean that will reportedly see a major Japanese bank extend a $500 million oil exploration loan to Brazil.

The visit comes as Chinese President Xi Jinping wrapped up a nine-day Latin American tour, as the Asian powers eye the region's fast-growing economies and vast natural resources.

A small plane making an emergency landing in Paraguay crashed into a motorbike, killing three people while the pilot survived and fled, police said Wednesday.

Leftist incumbent Dilma Rousseff maintains a lead ahead of Brazil's October presidential elections but could face a second round dead heat against her main rival, said a poll out Saturday.

Rousseff, who succeeded Luiz Inacio Lula da Silva four years ago to keep the Workers Party (PT) in office, would currently receive 32.2 percent of the vote, down from 31.6 in June, a Sensus Institute survey for news digest Istoe showed.

A judge in Rio de Janeiro Friday ordered 23 people jailed for "violence" during ant-World Cup protests, including those arrested before the Argentina-Germany final.

Colombian pop sensation Shakira, Mexican guitarist Carlos Santana, Brazilian singer Ivete Sangalo and a samba school lead the musical entertainment at Sunday's World Cup closing ceremony.

Following the opening song, Shakira performed at her third World Cup, and sang "La La La (Brazil 2014)" alongside home favorite Carlinhos Brown.