Sao Paulo, July 8 (EFE) A 17-year-old girl has confessed to the police that she participated in more than 30 murders since 2006, with all the killings committed with the same knife, a media report said.

The teenager told the police she confessed to clear her conscience and avoid being tried as an adult once she turns 18, the police commander in the city of Sao Jose do Rio Preto, Mauro Truzzi, told the media.

Truzzi told the Estado news agency that while it was too soon to know whether the teenager's story was true, she described at least 11 of the killings.

All the victims were adult males, the police commander said.

The majority of the killings occurred in Aparecida do Taboado, a town in Mato Grosso do Sul state, but the confession was made in Sao Jose de Rio Preto, located some 450 km from the city of Sao Paulo, where the girl had been arrested for taking part in a fight.