Heavy rains in Brazil's south kill at least 6 people, leave dozens missing

At least six people have died and more than a dozen are missing after storms caused flooding in the southern Brazilian state of Rio Grande do Sul.

Helicopters are flying over the region searching for people who have been left stranded.

In some areas, the flooding is so severe that helicopters have been unable to land and have had to winch residents to safety.

The state's governor has asked the federal government for help.