The helicopter came down and burst into flames, after the pilot was hit in the leg by a bullet.
At least 10 other people were reported to have died in the fighting. Several buses were also set on fire.
It was the worst outbreak of violence since the city was awarded the 2016 Olympic Games two weeks ago.
The attack on the helicopter followed an outbreak of fighting between rival drug gangs in a shanty town in the north of the city.
One resident said it was the one of the most intense gun battles he had witnessed in the area in recent years.
The police helicopter exploded after trying to make an emergency landing on a football field.
Two policemen were injured in the crash.
A new gun battle then began between the gangs and dozens of policemen.
In total, 10 alleged gangsters were reported to have been killed.
Authorities were not able to confirm if it was the first time that one of their helicopters had been brought down by gunfire. (Actually was the second time. The first was in the 1980´s. PS from Hogan)
Published: 2009/10/17 22:52:55 GMT
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