Brazilian authorities have issued arrest warrants for five people in connection with a dam collapse that killed at least 65 people as it plastered part of a city with reddish-brown mud and mining waste.

Firefighters on Monday carefully moved over treacherous mud, sometimes walking, sometimes crawling, in search of survivors or bodies, four days after a dam collapse that buried mine buildings and surrounding neighbourhoods with iron ore waste.

Workers with Brazilian mining company Vale were eating lunch Friday afternoon when the dam collapsed, unleashing a sea of reddish-brown mud that knocked over and buried several structures of the company and surrounding areas.