Police and residents of a shantytown in Rio de Janeiro have again clashed over the death of a dancer, raising fresh fears over security as Brazil prepares to host the football World Cup.

Trouble flared as protesters marched back from the funeral of Douglas Pereira, allegedly killed by police after being mistaken for a drug dealer.

His shooting on Tuesday had already sparked clashes then.

The 25-year-old’s mother, Maria de Fatima da Silva, claims he was tortured to death.

“I am almost sure that the gunshot wound didn’t kill him. He died because he was beaten afterwards,” she said.

Authorities in the city have pledged to fully investigate what happened to the dancer. Witnesses say another man was shot dead amid Tuesday’s unrest.

Football’s governing body Fifa insists the violence on the doorstep of Rio’s tourist area of Copacabana does not jeopardise the World Cup, due to start on June 12.