A 43-year-old man who was left in a coma after four young men attacked him April 28 on the platform of the Tokyu Denentoshi Line's Sangenjaya Station died at a Tokyo hospital Friday.

Akira Maki, who was employed by Chase Manhattan Bank and lived in Kawasaki, died of a subarachnoid hemorrhage around 7:45 a.m. Friday.

Police are searching for the four men on suspicion of inflicting injuries resulting in death.

Witnesses said Maki got off a local train bound for Chuorinkan Station around midnight on April 28. He reportedly held open the train doors and said something to a group of men inside the carriage before disembarking. The assailants then forced the doors open, got off the train and attacked Maki with their bare hands.

Passengers in the carriage said Maki and the men were arguing loudly after one of the parties to the incident apparently stood on another's foot. Investigators suspect this was the cause of the incident.

Police said the four men are aged around 20. Two are about 170 cm tall, one of whom was wearing a black baseball cap and the other a white cap. Police are distributing fliers with illustrations of the men's clothing in an effort to resolve the case.