Suspect identified in Taiwan train blast

A man who is in critical condition has been linked to a pipe bomb explosion on a Taiwanese metro train, which injured 25 passengers.

An explosion on a train in Taiwan has injured 24 people, many of whom are in a serious condition. (AAP)

A 55-year-old man has been identified as a suspect in the bombing of a commuter train in Taiwan that injured at least 25 people, state-run media say.

Police identified Lin Ying-chang after comparing fingerprints collected from the bomb and a bag left at the scene, the Central News Agency said on Friday.

Lin was also seen near the device when the incident happened, police said. He is in critical condition in a Taipei hospital.

The blast occurred in a moving northbound metro train about two minutes before it stopped at Songshan Station in the capital around 10pm local time on Thursday, police said.

A device made of pipe measuring 47cm in length by 6cm in diameter was found in the carriage.

Some pieces of it were collected along the track near the station, said Wang Pao-chang, chief of Taipei precinct of the Railway Police Bureau.

At least 25 passengers suffered from burns and smoke inhalation. Five of the victims were in critical condition, police said.