( CNN ) -- A bus packed with children burst into flames in Colombia on Sunday , killing at least 32 people , officials said . The bus was picking up children from an event at a church in Fundacion , Colombia , when the blaze began , Col. Adan Leon told CNN affiliate Caracol TV . `` Everyone started to scream and run , '' a child who was on the bus told Caracol , describing how he escaped through a window . Victims of the deadly fire included 31 children and one adult , Harry Aaron , a civil defense official in Magdalena department , told CNN . Authorities are investigating what caused the fire , Leon told Caracol . One witness told Caracol that the driver went to get a drink and left children to put gasoline into the vehicle 's tank . Colombian President Juan Manuel Santos expressed condolences on Twitter Sunday and traveled to the northern Colombian municipality to be with victims . `` The country is in mourning , '' he said . 48 die in bus crash . No evidence of fire before FedEx truck crashes into bus .
NEW : 31 children were killed when a bus caught fire . NEW : Colombia 's President is in the municipality where the bus fire occurred . The bus was picking up children from a church , police say . Comment: