At least five tribals are feared to have drowned when a boat they were on board capsized in the Patali river in Padua area here on Saturday evening.Sources said a group of villagers of Masiramput village was returning in the boat after purchasing vegetables and other items from a weekly market along the Andhra-Odisha border.After being informed, officials from the district administration and police rushed to the spot and undertook rescue operation in association with local volunteers.