Deadly protests have broken out in the Brazilian city of Rio de Janeiro following the death of a young man allegedly beaten by police.
A man was shot dead during the violence on Tuesday night in the Pavao-Pavaozinho neighbourhood.
Demonstrators from the favela set barricades of tyres alight, leading to the closure of streets in the nearby tourist area of Copacabana.
The violence comes weeks before Brazil hosts the football World Cup.
The unrest started after the discovery in Pavao-Pavaozinho of the body of Douglas Rafael da Silva Pereira, a 26-year-old professional dancer.
Angry residents marched to a local police station accusing the officers of beating Mr Pereira to death.
Witnesses said cars were set ablaze, the local police station was attacked and gunfire could be heard from the favela.
"There was smoke everywhere, shots in the street and people racing for their homes," one resident living nearby told AFP news agency.
Pavao-Pavaozinho is one of the poor neighbourhoods of Rio that has been part of the recent "pacification" programme, in which police move into an area in an effort to wrest control from the drug traffickers who run it.
It is an attempt by the city authorities to drive the heavily armed gangs away from the communities and restore police authority ahead of the football World Cup in June and July.
But the programme is controversial as Brazilian police have been accused of using excessive force, at times killing residents not connected to any gangs.
Amnesty International says some 2,000 people die every year in Brazil as a result of police violence.
"This effort to pacify the favelas is a failure; the police violence is only replacing what the drug gangs carried out before," resident Johanas Mesquita told the Associated Press news agency.
Mr Pereira's body was discovered in a local day-care centre covered in wounds.
According to some residents, he had been trying to flee from a shoot-out between police and drug dealers and had climbed over a wall to hide in the day-care centre.
They said he had then been discovered by the officers, who, believing he was a drug dealer, had beaten him to death.
The circumstances surrounding his death are under investigation, AFP news agency quoted police as saying.
"An on-site report indicates Douglas's injuries are compatible with a death caused by a fall," the police statement said.
But his mother said he was covered in boot marks, suggesting he had been kicked to death.
Large crowds, demanding an explanation for the death, gathered near the entrance to the favela, which is just a few streets away from the city's famous beaches and tourist hot-spots, reports the BBC's Wyre Davies from Rio.
The clashes began at 17:30 local time (20:30 GMT) causing panic among residents returning from work. Hundreds had to mill around in nearby streets waiting for the violence to stop to return to their homes.
Riot police and firefighters were sent to the area and an hour later witnesses reported hearing "an intense firefight".
Officials said a 27-year-old man was killed by a bullet to the head. It is not yet clear who fired the shot.
Riot police said they had "rescued" a group of 10 officers who had been surrounded by protesters inside the favela.
Police said the violence had been orchestrated by a powerful criminal gang.
Tony Teizeira of the Copacabana Residents' Association said the clashes came at a time when many tourists were in the area on Easter holidays.
"Unfortunately, innocent people are having to pay for this war between the police and drug traffickers," he said.
Thousands of visitors are expected to visit Rio for the World Cup which starts in Sao Paulo on 12 June and will end with the final in Rio's famous Maracana stadium on 13 July.