A Hasidic Jewish man was socked in the face in an unprovoked Brooklyn attack that authorities are investigating as a hate crime, according to police.

The 25-year-old man was walking with his family on Surf Avenue near West 10th Street in West Brighton Beach — dressed in traditional garb — around 4:30 p.m. Tuesday when a stranger suddenly punched him without saying a word, cops said.

The victim refused medical attention for a cut on his nose.

The NYPD Hate Crimes Task Force is probing the incident — though the reason for their involvement wasn’t immediately clear as the attacker didn’t make any comments, authorities said.

Cops say the suspect appeared to be black, around 6 feet tall, last seen wearing a dark T-shirt and black pants.