RIO DE JANEIRO, Feb. 20 (Xinhua) -- The death toll from Brazil's tragic dam disaster in southeast Minas Gerais state has climbed to 171, and 139 people remain missing, the state civil defense agency said Wednesday.

According to the agency, among the missing are 34 employees of mining giant and dam owner Vale and 105 subcontracted workers or residents of the area close to the dam.

Rescue teams continue searching for the missing.

The catastrophe occurred on Jan. 25 when a tailings dam that contained tons of toxic waste from an iron-ore mine collapsed, burying parts of the town of Brumadinho.

The sea of mud is believed to have washed away Vale administrative offices and a cafeteria where hundreds of people were having lunch when the dam broke.

On Wednesday, Vale announced that it was relocating 125 people living in area near the five mining deposit dams in Minas Gerais.