A gunman holding a busload of passengers hostage in Rio de Janeiro on Tuesday was shot dead by police, local media reported, ending the hours-long hijacking.Reports said the passengers on the bus were unhurt.At least 16 people were trapped on the bus after it was commandeered by the gunman on a heavily transited bridge connecting Rio with the neighbouring city of Niteroi.At least six people - four women and two men - were freed by the gunman who stopped the vehicle on a heavily transited bridge connecting Rio with neighbouring city Niteroi.Heavily armed police including military and snipers surrounded the bus as they negotiated with the gunman. The gunman reportedly boarded the Rio-bound bus at 5:30 am (0830 GMT) and began threatening passengers. Several lanes of traffic on the busy Rio-Niteroi bridge spanning Guanabara Bay were paralysed during the hostage situation.Rio state Governor Wilson Witzel said: The absolute priority is the protection of hostages. The gunman - a young man wearing a white T-shirt and dark-coloured trousers -- poked his head out of the bus at one point, showing his face, footage from local TV channel revealed.In 2000, a gunman stormed a passenger bus in a fashionable neighbourhood of the city. The hours-long hijacking of bus 174 was later turned into an award-winning documentary. The hijacker and one hostage were killed.