A public memorial ceremony was held Monday in Taoyuan, Taiwan to mourn the victims of a fatal tour bus fire that killed 26 people on July 19.

Authorities from both sides of the Taiwan Straits, including the Chinese mainland-based Association for Relations across the Taiwan Straits and Taiwan's Taoyuan municipal government, sent scrolls of elegiac couplets and flower baskets to mourn the victims.

Taiwan's former leader Ma Ying-jeou was among local representatives who mourned the dead at the ceremony.

Liu Kezhi, secretary-general of the Chinese mainland-based Association for Tourism Exchange Across the Taiwan Straits, and representatives of mainland enterprises in Taiwan also paid tribute to the victims at the service.

Everyone on board the bus was killed when it crashed into a highway barrier and caught fire near the Taoyuan Airport on July 19. 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 that the fire began near the driver's compartment, according to local prosecutors.

On Sunday, investigators found "gasoline components" in burnt plastic containers in the driver's compartment and the baggage area of the bus. Similar traces were also found on a carpet near the front door of the bus, and burned objects were found in the driver's compartment.

Local prosecutors said they are working to determine whether human error led to the accident.