At least seven people were killed Saturday in southeastern Brazil when a canyon wall collapsed on speedboats in a lake, according to local authorities.

The rockslide in Lago de Furnas near the city of Capitolio hit four boats and two sank, said local sources, while footage of the incident went viral on social media.

The Minas Gerais Fire Department said three missing people were found on a boat called Jesus that the rock directly hit.

Earlier, Fire Chief Edgard Estevo said 20 people were missing because of the accident. Search and rescue efforts continue and divers will take a break from their night work as it is risky.

Fire department spokesman Pedro Aihara told the Brazilian EPTV channel that some who were missing were found after contacting state hospitals.

After the accident, many victims went to hospitals in the state and 20 were listed as missing because there was no cross-listing, added Aihara.

It occurred "due to heavy rains, which caused the loosening of a wall of stones in Lago de Furnas, in Capitolio," Minas Governor Romeu Zema said on Twitter.

"The Government of Minas is present from the beginning through the Civil Defense and Fire Department. Rescue work is still ongoing," he added.

The navy will launch an investigation into the incident. (Anadolu Agency: Excludes headline)