More than 150,000 people in Paraguay, Argentina, Uruguay and Brazil have been driven from their homes by some of the worst flooding in years, BBC News reports.

Heavy summer rains have caused rivers to swell across a vast area.

In Paraguay, the most affected country, President Horacio Cartes declared a state of emergency, freeing up $3.5m in relief funds.

The Paraguay river in the capital, Asuncion, is just 30cm (12in) away from overtopping its banks.

That could lead to widespread flooding in the Asuncion area.

And it could affect thousands of other people who live by the Paraguay - the country's main river - the authorities said.

Nearly 200 electricity pylons have been damaged or destroyed by strong winds.

Four people were killed in the country by fallen trees.

In northern Argentina, some 20,000 people have been evacuated.

At least two people have died in the floods, which have mostly affected the provinces of Entre Rios, Corrientes and Chaco.