One person was shot dead as violent protests erupted Tuesdaynear Rio's famed Copacabana beach after a dancer was killed allegedly by police,less than two months before the World Cup in Brazil.Angry demonstrators from a slum set ablaze barricades of tires, forcing two mainroads closed as they hurled bottles to protest the death of the 25-year-old dancer,whom Brazilian media say was killed after police mistook him for a drug trafficker.A 27-year-old man described as mentally disabled was killed after being shot in thehead during the protests, media quoted city hall officials as saying. It was notimmediately clear who fired the shot.After waves of street protests last year over poor living conditions, the latest unrestwas yet another embarrassment for Brazil as the Latin American giant prepares tostage the World Cup in June and the Summer Olympics in 2016.Many in this emerging economic power are outraged that billions of dollars havebeen spent on infrastructure for the games instead of public housing, roads, moreaid for the poor and ending violent crime.The latest trouble began in the early evening in the Pavao-Pavaozinho favela, whichnestles above the well-heeled tourist centers of Copacabana and Ipanema, beforequickly spreading, witnesses said."It started around 5:30 pm. There was smoke everywhere, shots in the street andpeople racing for their homes," said a young man living just next to the favela, orslum.Another resident said electricity supplies had been cut in the area and the situationremained tense. The web site G1 reported violence had spilled over into Ipanema assome youngsters went on the rampage there, pursued by police. - 'Don't come to the Cup' Police have been cranking up efforts in recent months to clear favelas of violentcriminals before the month-long World Cup kicks off on June 12.Although a huge slum "pacification" program was launched six years ago toimprove security in the city, the gangs have been fighting back.Friends of the dancer, Douglas Rafael da Silva Pereira, alleged that he was caught ina shoot-out on Monday night between police and drug traffickers. He sought refugein a nursery school in the slum, but was beaten to death, they said.Police told AFP that evidence suggests the dancer died in a fall.Da Silva Pereira performed on a program on TV Globo that was popular with residents of the slum.The dead man's mother, nurse Maria de Fatima da Silva, said: "He died at one in themorning. More than 12 hours afterwards we got to see the body. He was in adefensive posture, all beaten up.""There were no signs of gunshot wounds," she added, saying that her son had goneto the favela to visit his four-year-old daughter. One resident of Pavao-Pavaozinho, Daizy Carvalho, who works for a human rightsgroup, said: "He was a mirror for youngsters who are in revolt. What kind of WorldCup is this?" she asked."The people from the favelas need to unite and come out onto the street," she toldAFP, calling on tourists "not to come to the Cup".Carvalho also claimed that police had insulted her and that one officer said theywere going to "kill a young person to set an example.