A Jewish grandmother was slugged in the back of the head by a young thug in Brooklyn Monday — and cops suspect it may be another instance of the violent “knockout game.”

The attacker didn’t say a word or try to rob the 72-year-old Mira Harpazi, police sources said.

She had left her home in Starrett City to visit a Jewish community center in Canarsie.

She went to a nearby pharmacy and was returning to the center at around noon when the thug attacked her on the corner of Pennsylvania and Flatlands avenues.

The NYPD’s Hate Crime Task Force is looking into whether the attack was an occurrence of the knockout game — a disturbing trend in which thugs sucker-punch passers-by, with the goal of rendering them unconscious.

Harpazi was not knocked out. She was treated at Brookdale Hospital and released.

The attacker, believed to be in his late teens or early 20s, was still at large Monday night.

A neighbor at Harpazi’s East New York apartment was shocked about the attack, but said the grandma is one tough cookie.

“Miriam is all the over place, she’s very independent,” said Barbara Fulton, 56. “She’s a tough woman.”

“She has a lot friends. I’m surprised. I don’t know why anyone would want to punch her.”

Meanwhile, police made an arrest Monday in another suspected knockout in Crown Heights where a 12-year-old boy was slugged.

Cops nabbed a 13-year-old and charged him with assault and aggravated harassment as a juvenile for the Nov. 6 attack.

Since Oct. 11, at least eight suspected knockout attacks have been reported in Brooklyn — in the Crown Heights, Midwood and Borough Park sections.

Police are investigating the cases, in which the victims, often Orthodox Jews, were struck by one thug as others looked on.

Harpazi, who is not Orthodox, did not report seeing any other people in the area at the moment she was assaulted

But police are seeking any witnesses and video evidence that it was a knockout-game attack.

The game — sometimes called “polar bear hunting,” because most victims are white — has been fueled by social media, with thugs boasting of their attacks online and posting Internet videos of the sucker punches.