Taiwan's Central News Agency cited police as saying they suspected the tonight blast in the capital of Taipei had been caused by some kind of explosive in the train carriage.
The news agency cited the director of Taiwan's National Police Agency, Chen Kuo-en, as saying late today that the explosive appeared to be 15 to 20 centimeters (6-8 inches) long and looked like a firecracker.
The report says the self-ruled island's premier, Lin Chuan, ordered government agencies to form a team to investigate the blast.