A man is in the Hennepin County jail after allegedly assaulting an acquaintance with a hammer on a Blue Line light-rail train Friday night.

Several passengers called 911 about 7 p.m. to report that two men were fighting on the train near the 46th Street station, according to Metro Transit spokesman Drew Kerr.

The two men knew each other, Kerr said. The aggressor was restrained by passengers, who took away the hammer, and arrested, he said. The man he hit with a hammer was taken to a hospital of treatment of what Kerr called “minor injuries.”

The incident briefly delayed Blue Line traffic.