A suspected pipe bomb injured 25 people on a passenger train in the Taiwanese capital late on Thursday, officials said.
A 38-year-old Vietnamese woman was among the injured, Vietnamese news website reported.
The blast shook Taipei's Songshan station close to midnight and witnesses quoted on Taiwanese television described seeing a man leaving a long black device on the train just before the explosion.
Premier Lin Chuan told Taiwanese television the blast appeared to be a deliberate "act of malice".
Police and the Taipei fire department said a "steel pipe" was the origin of the blast.