At least 10 people were killed and 31 injured when a bus carrying students on a hiking trip crashed in Brazil, police said Tuesday.

"They were traveling on a bus for a school trip," a police spokesman told AFP.

U.S. President Barack Obama congratulated his Brazilian counterpart Dilma Rousseff on her re-election Monday, the day after the left-wing incumbent won a narrow victory in a presidential run-off vote. 

"Brazil is an important partner for the United States and we are committed to continuing to work with President Rousseff to strengthen our bilateral relationship," the White House said.

Leftist President Dilma Rousseff vowed to reconcile Brazil, reboot the economy and fight corruption after narrowly winning reelection Sunday in the most divisive race since the return to democracy in 1985.

Rousseff, the first woman president of the world's seventh-largest economy, took 51.6 percent of the vote to 48.4 percent for business favorite Aecio Neves in a run-off election.

After a contentious campaign, Brazilian polls opened amid tight security Sunday as voters headed out to elect their next president.

Some 143 million people in the world's seventh-largest economy were choosing between leftist incumbent Dilma Rousseff, who final opinion polls showed had a narrow edge, and Social Democrat Aecio Neves, scion of a famous political family.

After a no-holds-barred campaign, Brazil's leftist leader Dilma Rousseff is the favorite heading into a presidential run-off election Sunday against bruised center-right challenger Aecio Neves.

As the hard-fought race to lead the world's seventh-largest economy entered the final stretch, two opinion polls released Thursday gave Rousseff -- looking to extend 12 years of Workers' Party (PT) rule -- a six- to eight-point lead over Neves, the business-world favorite.

In Brazil, women primarily wear their hair long, and need to tackle the country's generally hot, humid climate when they style it. They also demand a wide range of sun protection creams.

Beauty industry giants such as L'Oreal, Unilever and Procter & Gamble that are looking to crack key emerging markets like Brazil are quickly adapting their product lines to suit local tastes.

Leftist incumbent Dilma Rousseff and Social Democratic challenger Aecio Neves are fighting to break a statistical tie in the polls a week out from next Sunday's presidential runoff.

The contest has developed into the closest-fought in a generation as Neves, scion of a political dynasty, looks to unseat Rousseff, whose Workers Party (PT) has been in power for 12 years.

Inmates at a prison in southern Brazil ended a two-day uprising Wednesday after releasing guards and other prisoners they had taken hostage, officials said.

A spokesman for the Parana state's justice secretary said 28 prisoners will be transferred from the jail in Guarapuava to other detention centers in the state and in neighboring Santa Catarina state.

Negotiations resumed Tuesday at a Brazilian prison where rioting inmates took 12 guards and several fellow prisoners hostage, the latest in a series of uprisings.

"There is no one demand that has been communicated," a spokeswoman for the state justice department said, adding that "we know some inmates are seeking transfers."

Negotiations resumed Tuesday at a Brazilian prison where rioting inmates took 12 guards and several fellow prisoners hostage, the latest in a series of uprisings.

"There is no one demand that has been communicated," a spokeswoman for the state justice department said, adding that "we know some inmates are seeking transfers."