Police used stun grenades and tear gas to clear protesters in the path of the Olympic torch in a poor suburb of Rio de Janeiro, two days before the Olympic Games open.
Olympic Brazilian sailors earlier delivered the torch to the host city's mayor after crossing Guanabara Bay near the end of a 20,000km journey.
The flame landed on terra firma at 9.15am local time while just kilometers away 450 heavily armed police battled drug traffickers to carry out dozens of arrest orders in the Alemao slum.
The area is near the international airport and close to the main road to Olympic venues.
Armed soldiers stood patrol on highways and on many corners throughout the iconic beach city in Brazil's largest security operation ever.
About 85,000 police, soldiers and security personnel will be deployed in Rio, more than double the amount in London in 2012, to deter both violent street crime and the threat of attacks by extremists.
Police said anti-government protesters in Duque de Caixas threw rocks and blocked the torch's path.
Police dispersed them with pepper spray and rubber bullets.
A video of the incident spurred social media criticism of the police and amplified complaints that the Games ignored the poor.
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.
Three people were injured by rubber bullets, including a ten-year-old girl, local media reported.
The clash, which came a day after anti-torch protests in nearby towns and amid several days of gang violence in northern Brazil, underscored social tension in the massive country.
The world's largest sporting event comes to Brazil at a challenging time, in the midst of the country's worst recession in at least a quarter century and an impeachment trial of a suspended president.
Many residents struggling with the dire economy question the wisdom of hosting the costly Olympics, a bid Brazil won in 2009 while the economy was booming.
The symbol of the Olympic Games will visit more towns and return to the city centre ahead of tomorrow's opening ceremony in the famed Maracan stadium, site of the World Cup final in 2014.
