There are fears of water contamination after a bridge collapsed in northern Brazil at the weekend, sending lorries carrying thousands of litres of pesticides and sulphuric acid into the river below.
Four people are known to have died, and more than 10 are missing after the central span of the bridge linking Tocantins and Maranhão states gave way on Sunday afternoon.
It is not clear if or how much the chemicals have leaked from their containers, but diving operations in the river have been halted while the situation is assessed.
Dramatic video filmed by a local councillor who went to the bridge to draw attention to cracks in it showed the start of the collapse.
Councillor Elias Junior said he never expected the bridge to actually collapse when he was there and was “in shock”.
Eight vehicles plunged into the river, including the three lorries containing chemicals.
People in the cities of Estreito and Aguiarnopolis, on either side of the river, have been told to avoid collecting water from it.
Rescue operations are being carried out from boats. Four bodies have been recovered, including the female driver of one of the trucks and an 11-year-old girl, the fire service said. One man was rescued alive from the water on Sunday.
The Juscelino Kubitschek de Oliveira bridge – which is more than half a kilometre (1,600ft) long – was built in the 1960s and is the main link between the two states across the Tocantins river.