Tour bus catches fire on highway to the Taiwan Taoyuan International Airport in Taiwan, July 19, 2016. Twenty-six people, including 24 mainland tourists, died in this accident.[Photo by China Times/Asianewsphoto]

TAIPEI -- Investigators have found "gasoline components" in burnt plastic containers in the driver's booth and baggage compartment of the bus which caught fire in Taiwan on Tuesday, killing 26 people.

Wang Yi-wen, deputy chief prosecutor of Taoyuan District Prosecutors Office, told the press on Sunday that similar traces were also found in a carpet by the front door of the bus and burnt remains in the driver's compartment.

Investigators are trying to figure out if gasoline was stored in the bus and investigating the relationship between the fire, the gasoline components and the source of the gasoline containers.

Everyone aboard the bus was killed when it crashed into a highway barrier and caught fire near Taoyuan Airport on Tuesday. They included 23 tourists and a tour guide from the Chinese mainland, a local driver and a local tour guide.

A preliminary investigation found evidence to suggest the fire began in the vicinity of the driver's compartment, local prosecutors said Friday.