Edgar Estevo, director of the Minas Gerais Fire Department, said during a press conference that 20 people may be missing in addition to the six victims, noting that the authorities are seeking to establish their identities after the accident.
Officials said at least 32 people were injured, but the majority of the wounded were discharged from hospitals on Saturday evening.
Video recordings showed a group of boats moving slowly near the high cliff, when a mass of rock separated from the cliff and fell on top of at least two boats.
Estevo said the accident occurred between the towns of São Jose da Barra and Capitolio, from which the boats set off.
The media office of the state of Minas Gerais told “The Associated Press” that the fire department has deployed divers and helicopters to provide a helping hand.
Romeo Zima, governor of the state of Minas Gerais, sent messages of solidarity with the victims on social media.
Lake Furnas, which was formed in 1958 as a result of the construction of a hydroelectric power station, is a well-known tourist attraction in the region, 420 kilometers north of São Paulo.
Officials in Capitolio, which has a population of about 8,400, say the city could see about 5,000 visitors on weekends, and up to 30,000 on holidays.
Officials indicated that the collapse of the rock mass may have been caused by the torrential rains that caused floods in the state and forced nearly 17,000 people from their homes.
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