A preliminary investigation into Tuesday's tourist bus fire in Taiwan has indicated a circuit fault caused the accident.

A group of four officials from the Chinese mainland arrived in Taiwan on Wednesday. They asked authorities from Taiwan to ensure similar accident would not happen again. 26 people, including 23 tourists and a tour guide from the Chinese mainland, were killed in the bus fire.

"Our trip has two goals: one is to mourn the victims and send our condolences to their families; the other is to start negotiations with the Taiwan Strait Tourism Association to deal with the accident," Liu Kezhi, secretary-general of the Association for Tourism Exchange Across the Taiwan Straits, said.

Family members of the Chinese mainland victims are scheduled to arrive in Taiwan on Thursday. Taiwan authorities held a meeting on the accident and observed a one-minute silence for the victims. Investigators will hear a special accident report from the local transportation department on Thursday. 21 buses of the same model as the one involved in the accident have been ordered off the road to undergo safety checks.