The streets of the Brazilian city, which will play host to the Olympic Games in August, have been filled in recent days with people celebrating in advance of its famous carnival, which officially begins on February 5.
The shooting occurred as the musical group "Ceu na Terra" was parading before a crowd of some 8,000 people yesterday in the Santa Teresa district of central Rio.
"Three people were wounded and one of them has died," a military police spokesman told.
But with the Olympics only months away, Rio remains a dangerous city, with regular clashes between criminal gangs and the police and at least three murders every day, mainly in the poorer neighborhoods.