Light-rail service was interrupted late Friday morning in St. Paul after an argument between two juveniles escalated into a shooting.

Two teenage boys who knew each other got into a fight as a Green Line train was stopped at the Lexington Avenue station. As one of the teens left the train, he fired a shot and a bullet struck the other boy in the arm, said Metro Transit spokesman Howie Padilla.

The injured teen was not seriously hurt, Padilla said.

Green Line service was suspended just before 11 a.m. between the Capitol/Rice Street and Fairview Avenue stations after the incident. Riders were directed to use Route 16 buses until service resumed about 30 minutes later.

The teen who allegedly fired the shot was arrested by Metro Transit police with help from St. Paul police.

Metro Transit police are investigating.