An environmental emergency has been declared in towns in two Brazilian states after a chemicals reservoir burst and contaminated two rivers. The spillage occurred at a wood pulping factory at Cataguazes in Minas Gerais state, and much of the toxic waste is running into next-door Rio de Janeiro state. About 1.5 billion litres (396 million gallons) of caustic soda flowed into the Paraiba do Sul and Pomba rivers, according to the Rio de Janeiro state government website - although other reports have estimated the spill at 20 million litres (5.28 million gallons). People living near the rivers have been warned not to drink or bathe in river water, amid reports that 100 animals on the river banks have already died, along with hundreds of fish.