At least 51 people died on Saturday when a passenger bus drove off a cliff in the southern Brazilian state of Santa Catarina, police said.
The police said that two more people were trapped under the wreckage and "would likely take the death toll to 53."
The bus, which was traveling en route from the neighboring state of Parana, swerved off a curve and fell 400 metres (1,300 feet) before crashing into a wooded area. Rescue crews were still trying to rescue survivors and recover the bodies of the victims late in the day.
Santa Catarina state road military police commander Edilson de Tolledo told The Anadolu Agency earlier on Saturday that preliminary investigations appeared to show that the bus experienced brake failure and lost control on one of the ridge's numerous tight bends.
Police did not know how many passengers in total were aboard the bus or whether the driver was one of the victims, but said that at least six survivors were being treated for injuries.
Brazil has some of Latin America's deadliest roads. Despite nearly a decade of sustained economic growth that has only slowed in recent years, the country has done little to improve or expand its creaky infrastructure.
The country averages more than 18 highway deaths per 100,000 people per year, compared with about 10 in high-income countries, according to a report by the Inter-American Development Bank.