Using maracas, coca leaves and a hallucinogenic brew, shamans in Peru got down to business Monday using pre-Columbian traditional ceremonies to pick a winner in the US presidential race.

"The apus (gods of the hills in indigenous mythology) tell us (Barack) Obama will be reelected," predicted Juan Osco, known as the Shaman of the Andes on San Cristobal hill overlooking Lima.

Members of the group placed flower petals on photos of the candidates that were also swept over with tobacco smoke. The shamans chewed coca leaves, a traditional ceremonial and medicinal plant since Inca times that helps fight altitude sickness.

And the crew took some swigs of ayahuasca, a psychoactive brew used widely among Amazon basin indigenous people. At least one thing was clear, they said: Obama should defeat Republican Mitt Romney on Tuesday.