A small train overturned in the Ali Mountain area in Taiwan, southeast China, April 27, 2011. [Photo/Xinhua]

TAIPEI - A small train overturned in Taiwan's Ali Mountain area on Wednesday, killing five tourists from the Chinese mainland and seriously injuring at least 50 passengers who are members of five mainland tour groups.

The injured have been sent to hospitals in Chiayi.

Witnesses say branches of a tree had fallen over the railway line, which hit the last carriage and then caused several carriages to overturn.

Liu Kezhi, director of the Cross-Strait Tourism Exchange Association's Taipei office, has reported the accident to the association and asked Taiwan's relevant department to make its best efforts to take care of the injured mainland tourists.

Liu will be visiting the accident site together with his colleagues.

The Taiwan Affairs Office of the State Council and the National Tourism Administration immediately launched an emergency mechanism to handle the accident.

The Association for Relations Across the Taiwan Straits also contacted the Straits Exchange Foundation (SEF), urging all-out rescue efforts from Taiwan's relevant departments.

The relevant departments of mainland would keep in contact with Taiwan counterparts, actively safeguard the rights and interests of mainland tourists' and properly handle the aftermath of the accident, according to a press release from the Taiwan Affairs Office of the State Council on Wednesday evening.

Among the dead are three people from southern Guangdong Province - Ye Yinxian, Ye Qiongzhen and Peng Zhenqu, and two from southwestern Sichuan Province - Chen Daohua and Zhuo Peiqun, according to Taiwan authorities.

The identities of the injured mainland tourists are being confirmed.

Ali mountain, or Alishan, is one of Taiwan's premier tourist attractions for mainland tourists. A similar train accident occurred near to that of Wednesday's one nine years ago, killing 17 and injuring more than 150 people.

The Alishan rail line, running east from the southern city of Chiayi, goes through steep mountains.

According to Taiwan authorities, 1.82 million mainland tourists visited the island on tour packages from July 2008 to the end of 2010.

Last October, 19 tourists from southern coastal city of Zhuhai, Guangdong province, went missing after their bus was hit by a landslide during a storm in northeast Taiwan.