BLOOMINGTON — A man riding on a light rail train in a Minneapolis suburb fatally stabbed a fellow passenger early Thursday following an argument, transit officials said.

The argument between two men turned into a physical fight after the northbound Blue Line train left the Mall of America station in Bloomington about 1 a.m., a Metro Transit official said.

One of the men pulled out a knife and stabbed the other, according to Metro Transit spokesman Howie Padilla. Police arrested the assailant without incident when the train stopped at another station, he said.

The victim, who has not been identified, was taken to Hennepin County Medical Center in Minneapolis, where he died.

Security cameras and witnesses on the train were helping investigators piece together what happened, Padilla said.

“They feel that sooner, rather than later, they’ll pull together a case for the Hennepin County attorney,” he said.