Police are searching for a man who slashed a subway rider's face before attacking three others, including two who wouldn't give him money early Wednesday morning.

The heavyset suspect first punched a 35-year-old man in the right side of his face, holding the exposed blade of a box cutter, on the northbound No. 4 train at about 1:20 a.m., police said.

Both men got off the train at Union Square and the suspect tried to flee. He then ran into a 20-year-old woman and slapped her.

The suspect ran up the stairs and approached a 46-year-old man standing near the Food Emporium, asking him for $2. When the man refused, the suspect slashed the right side of his face, police said.

He then crossed the street and tried the same thing with a 59-year-old man who was waiting for the M14 bus, this time asking for $1. The man refused and the suspect slashed the right side of his face as well before running away.

All of the victims were taken to Bellevue Hospital Center in stable condition.