A 40-year-old man was shot while riding the CTA Red Line Tuesday night in the Fuller Park neighborhood on the South Side, police said.

He was fighting with two other men on the northbound train as it approached the 47th Street stop around 8:10 p.m. when someone pulled out a gun and shot him, according to Chicago police.

He was taken to University of Chicago Medical Center in fair condition with a gunshot wound to the leg, police said.

No one is in custody and Area 1 detectives are investigating.