Day of bloody chaos in Rio

Brazilian officials are insisting security won't be a problem for the 2016 Olympics, despite drug-gang violence yesterday that plunged Rio de Janeiro into a day of bloody chaos just two weeks after it was picked to host the games.

An hours-long firefight between rival gangs in one of the city's slums killed a dozen people and injured six.

A police helicopter was shot down and eight buses set on fire. Two officers died and four were injured when bullets from the gang battle ripped into their helicopter hovering overhead, forcing it into a fiery crash landing on a soccer field. Gunfire on the ground killed 10 suspected gunmen and wounded two bystanders.

Authorities said the mayhem would only toughen their resolve to improve security ahead of the Olympics and before 2014, when Brazil will host the World Cup football tournament with key games in Rio, the country's second-biggest city.