Police in Brazil have arrested five people as part of an investigation into Friday's dam collapse in Brumadinho.
At least 65 people died when toxic sludge engulfed a company canteen and neighboring residential buildings.
Prosecutors in Brazil say three of those arrested were officials from the mining company Vale, whose responsibilities included dealing with environmental impact licenses.
Vale said it was co-operating with prosecutors.
The company is the world's biggest producer of iron ore and nickel.
Two engineers working for a subsidiary company were arrested in Sao Paulo.
All five can be detained for 30 days and will be questioned by investigators in Belo Horizonte.
Rescuers are continuing to search for survivors in Brumadinho. Nearly 300 people are still missing and there is little hope they will be found alive.