A man allegedly groped a 13-year-old girl on a Bronx-bound subway train, police said.

The teen boarded a No. 4 train at 125th Street in Harlem on March 26 at 5:50 p.m. The suspect, who was already on the train, approached the girl and began to grope her, according to police.

The victim got off the train at 161st Street, and the man followed her out, police said. The suspect then fled.

The man is described as being between the ages of 20 and 40. He was wearing a black coat and carrying a black duffle bag during the attack, according to police.

Anyone with information regarding the incident should call the NYPD's Crime Stoppers Hotline at 800-577-TIPS. Tips can also be submitted at nypdcrimestoppers.com.