A man was seriously wounded in a shooting Friday night on a Green Line train as it pulled into a Near West Side station. Two people were taken into custody for questioning.

The 30-year-old man who was shot was arguing with two other males on the train as it pulled into the Ashland station, 1601 W. Lake St. about 7:20 p.m., according to Chicago Police Chief of Patrol Fred Waller.

The men began to fight and a gun discharged; the bullet struck the man in his left shoulder, police said. He was taken to Stroger Hospital in serious condition.

Chicago Police Chief of Patrol Fred Waller updates reporters about a shooting that occurred Friday night on a Green Line train at the Ashland station. | Sam Charles/Sun-Times

Two people of interest were taken into custody for questioning and a gun was recovered, according to police spokesman Anthony Guglielmi. It was not immediately clear whose gun it was and investigators were reviewing the station’s security footage to determine what happened.

Guglielmi said it is possible the man was wounded by his own gun.

Service on the Green and Pink lines was restored by about 9:15 p.m., the CTA said. Trains had been halted on both lines while police investigated.

Friday night’s shooting was the second at a CTA station in less than a month.

A 23-year-old man was shot Aug. 17 on a Howard-bound Red Line train soon after it pulled into the the Jackson Station in the Loop. Kornell Strenger, 24, of the Gresham neighborhood, faces felony charges of attempted murder and aggravated battery/discharge of a firearm in connection with that shooting.