Officials and media reports say a Turkish bus has hit a road sign, rolled over to its side and burst into flames, killing at least 10 passengers. Governor Dursun Ali Sahin said Wednesday the victims burned to death trapped inside the bus while a further 20 passengers suffered burns. Sahin said some of the passengers are in serious condition and he fears the death toll could increase. The bus was traveling from Istanbul to the Black Sea city of Trabzon when it crashed early Wednesday in the black sea province of Giresun, near Istanbul, according to a report of the Associated Press. Authorities are investigating the cause of the accident and why the driver lost control.