A 29-year-old woman was cut on her hand aboard a Brooklyn subway train after an argument with another straphanger Tuesday night, police said.

“I will chop you up on this train," the suspect said before he allegedly started to hit the woman with an object that was wrapped in a cloth at about 9:30 p.m. on a southbound No. 3 train in Prospect Heights.

The woman and the suspect got into an argument after she bumped into him at the Atlantic Avenue station and began yelling at each other aboard the 3 train, police said. As the train approached the Eastern Parkway station, the suspect pulled the wrapped object from his bag and used it to cut the woman, according to police.

The 29-year-old woman called 911 and was taken to area hospital, where she was treated and released.

The suspect fled the scene and has not been caught, police said. Anyone with information about the assailant should call Crime Stoppers at 1-800-577-TIPS.

The attack was the latest in a string of unrelated slashings in the city in recent weeks.

A 71-year-old woman needed 20 stitches after being slashed in the face aboard a D train in Manhattan Monday morning.

Last week, a man was left partially paralyzed in the face when a stranger attacked him on an East Village street, and a woman was slashed in the face while walking to work in Chelsea earlier this month.

The NYPD says slashings in the month of January are up 18 percent in 2016 compared to last year.

NYPD Commissioner Bill Bratton says "in many instances, there isn't a motive."

Forensic psychologist NG Berril notes that attackers may also have an advantage in the winter.

"People are bundled up, they don't have the same range of motion. They don't look around, they're just in their own worlds," said Berril.

-- Ida Siegal contributed to this report