The suspect, who hadn't been arrested as of Wednesday, is in his 30s, 6 feet tall and wore a black sweater with a multi-colored baseball cap, police said. View Full Caption NYPD

MANHATTAN — A straphanger dragged an 11-year-old boy between two subway cars and threatened to throw him off until a good Samaritan intervened, police said.

The boy had been on the southbound 4 train about 3:20 p.m. Oct. 5 when the man came onto the train with an associate and started fighting each other, an NYPD spokesman said Wednesday.

The pair started talking to the boy, but one got annoyed and grabbed him, pulling him between the cars, the spokesman said.

The suspect picked up the boy and shook him as if he was going to throw him off, police said.

Suddenly, a 26-year-old woman intervened and managed to pull the boy back inside, police said. She helped the boy off the train at Union Square while the suspect stayed behind, police said.

The boy, whose head was hit against the cars during the incident, refused medical attention, police said.

The suspect, who hadn't been arrested as of Wednesday, is in his 30s and stands about 6 feet tall. He wore a black sweater with a multi-colored baseball cap, police said.

Anyone with information should contact Crime Stoppers at (800) 577-TIPS (8477).