Five people have been killed and 10 others injured in a fire inside a Guatemalan passenger bus that police say may have been caused by an arson attack.
National police spokesman Donald Gonzalez said investigators have not ruled out mechanical causes. But he acknowledged that some witnesses say the bus was attacked.
Firefighter Carlos Hernandez told a local radio station that someone tossed a fire bomb at the bus in the capital, Guatemala City.
Street gangs have demanded protection money from bus drivers on the route in the past and killed drivers who refused to pay. Rights activists say 60 drivers were killed in 2010.