Footage appears to show a woman being hit by a projectile, fired by a policeman. She suddenly falls to the ground after a heavily-armed officer lifts his weapon. She was helping a young man who himself appears to have been shot and limped away clutching his leg.
Hundreds of protesters chanted angrily at the £9 billion cost of hosting the international event, as the torch moved through the city. Police said anti-government protesters in Duque de Caixas, on Rio's north side, threw rocks and blocked the torch's path, and were dispersed with rubber bullets and pepper spray.
Three people were injured by rubber bullets, including a 10-year-old girl, local media reported.
Footage from local news site The Caxiense shows tear gas being let off into the crowd as up to 10 policemen, who are wearing helmets and holding shields, clear a path down the road.
A representative for the local organising committee called the incident isolated and said the protesters had held up the torch but its route was not changed.
It is the latest in a series of clashes between Brazilian authorities and protesters.
Teachers who said their wages had yet to be paid succeeded in stealing the Olypmic torch during its lap of Angra dos Reis and snuffing out the flame on 28 July before being chased away by the military.
And as Eduardo Paes, the mayor of Rio, held the torch high on his circuit of the area on Wednesday, protesters from the São Gonçalo area continued to threaten to put out the flame.
Others chanted: "While the torch passes lit in Itaborai [a city nearby], jobs, health and education are put out."
At one point during the procession, torchbearers were reportedly forced to take shelter near a police station.
Controversy over the Olympics has made the torch a symbol of social discontent in the country as education and health remain underfunded and many government employees say they are still waiting for their wages to be paid.
Over 80,000 police and security staff are being used in Rio, which is double the amount used for the London Games in 2012.
Away from the protests, the build-up to Rio has seen traffic jams bringing the city to a halt as express lane for athletes and officials come into use.
Additional reporting Press Association
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