A Harlem school aide with a history of violence attacked a 6-year-old student, leaving the little boy traumatized with a ripped shirt and “deep scratch marks across his chest,” a new $10 million lawsuit charges.

The shaken child came home Dec. 7 and told his mom that “an adult with a green shirt and a beard aggressively grabbed him by his shirt and dragged him,’’ according to the Manhattan Supreme Court suit.

The mom, Bernadette Torres, rushed to the school, PS 194 Countee Cullen, and confronted her kindergartner’s teacher, the suit says.

The teacher identified her son’s attacker as an aide, “Mr. Kaseem,’’ the papers say.

A schools source identified him as Kaseem Gordon.

Other parents told Torres that the aide also “assaulted their children but that the school never took any action against him,’’ the suit says.

Torres met with the school’s assistant principal, Kerianne Harrison, and the aide four days later — and “Mr. Kaseem’’ tried to explain away the attack by saying he was breaking up a fight between her child, identified in the suit only as “JL,’’ and another boy, the documents say.

When the aide couldn’t provide the other boy’s name, he then switched his story, claiming that he “may or may not have ripped JL’s shirt’’ dragging him off a stage, the suit says.

“Which one was it: You was breaking up a fight with another student, or you was pulling him off the stage so he wouldn’t hurt himself?’’ Torres said angrily to The Post on Tuesday.

Torres said the principal and the aide’s supervisor later both “admitted that Kaseem attacked JL and acknowledged Mr. Kaseem’s troubled past of assaulting students but concluded that he would remain employed at the school,’’ according to the suit.

“It was sad how the school turned a blind eye on a serious moment,’’ Torres told The Post.

She added in her suit, “Mr. Kaseem has a history of assaulting students at the school, including instances of smacking, pushing and aggressively grabbing elementary school students.

“Mr. Kaseem’s actions that were known to the school and condoned by its administration.’’

Gordon — reached by phone by The Post on Tuesday — claimed to not know anything about the incident.

“This is all new to me,’’ he said. “It’s so hard in that school — so many fights on a daily basis, I don’t know this incident.’’

The aide was suspended pending an investigation, the city Department of Education said in a statement.

“The safety of students always comes first, and this individual has been suspended from working in our schools since February,’’ the DOE said. “The Law Department will review the legal complaint.”

A schools source said the aide was not a DOE employee but instead hired by an independent contractor.

Meanwhile, Torres said her son “loved school,’’ but now, “I basically have to bribe him to go.’’

The school is the same one where a teacher was jailed last year for shoving a student.

Additional reporting by Kate Sheehy