A man was slashed Sunday in the sixth such attack in New York's subways and on streets this year — following a spate of blade-wielding assaults in public places that started in the fall, police said.

The 27-year-old victim was rushed to a hospital to stitch the gash on his face just after the 3 a.m. incident on a Harlem station platform.

He'd been waiting for a No. 2 train and arguing with a woman; when she asked another man for help, he cut the victim and fled, police said.

Last Monday, a 71-year-old woman was slashed by a man on a train pulling into Manhattan's Broadway-Lafayette station. And the next day, a 29-year-old woman was cut on her hand when she bumped into a man who attacked her with a machete on a train in Brooklyn after they argued, police said.

Suspects have been arrested in both cases.

Earlier in January, a man was left partially paralyzed in the face when a stranger attacked him on an East Village street; a suspect was arrested.

Also in January, police caught up with a man they say slashed a woman in the face while she was walking to work in the Chelsea neighborhood. And another woman was robbed and slashed by three men at a Brooklyn subway station.

Authorities are looking for connections — or possible copycats — among the series of slashings that started in October with the apparently random attack on a guest in a Chelsea hotel.

In November, playwright David Henry Hwang was suddenly stabbed on a street in his neighborhood, Brooklyn's Fort Greene. And police reported four slashings in December, one in the subway and the rest on streets.