Charges are pending Tuesday for a 31-year-old man who allegedly slashed another man with a sharp object, critically injuring him, on a CTA Red Line platform in River North, Chicago police said.

Police responded to reports of a fight at the platform in the 500 block of North State Street at about 10:30 p.m. Monday and said a preliminary investigation determined two men, 31 and 48, had been in a “verbal altercation” on a CTA Red Line train.

The argument spilled out onto the platform where the 31-year-old pulled out a sharp object and slashed the older man several times on his back and neck, police said. The victim was taken to Northwestern Memorial Hospital in critical condition.

The suspect was arrested and taken to Rush University Medical Center in fair condition with lacerations to his hands, according to police.

CTA trains bypassed Grand for several hours overnight, starting at about 11:19 p.m., though service was returned to the station at about 3 a.m., according to the CTA.