The deputy chief of the TRA, Lu Chieh-shen, earlier told a press conference that the train was only six years old and had been in "pretty good condition" before the accident.

It remains unclear what caused the train to derail, but witnesses told local media they heard a loud noise then sparks and smoke.

Video footage on local television showed passengers breaking windows to escape the carriages.

"I smashed the safety glass and crawled out and I helped to pull a young man out," one passenger had told reporters. "There was a person sitting behind me. I'm not sure she survived."