Three innocent bystanders, including an 8-year-old girl and her father, were wounded when a gunman opened fire during an argument outside a Harlem supermarket on Saturday night, according to police.

The shooting took place shortly after 7 p.m. outside the Fine Fare at 130 Lenox Ave., police said.

“I was busy with customers when I heard the gun,” Reda Khater, 36, who was working at a halal food truck across the street, told The Post.

“One, two, three gunshots. Then I see a lot of police.”

Cops responding to a 911 call found a 33-year-old woman with a gunshot wound to the right arm outside the market.

She was taken to Mount Sinai Hospital, where she was listed in stable condition.

Police later learned that two other shooting victims — the young girl, who was hit in the right knee, and her 39-year-old father, who was wounded in the right arm — had walked into NYC Health + Harlem Hospital for treatment.

Both were listed in stable condition, police said.

According to police, the victims were not the shooter’s intended target.

No arrests have been made but detectives from the 28th Precinct are investigating, the department said.