A Texas daycare is accused of allowing a classroom to become a “child fight club” when a teacher allegedly encouraged her own son to attack a 4-year-old boy, according to a lawsuit.

Heather and Richard Harris claim Arka Montessori Academy of Risinger in Fort Worth failed to protect their son, identified in court papers as UH, during the April 27 incident in which teacher Chynia Johnson allegedly grabbed, shook and dragged him before causing him to crash onto a hardwood floor.

The parents allege Johnson, whose son had been fighting with UH, repeatedly manhandled the 4-year-old and tried to force the children back into a confrontation while another teacher stood by and failed to intervene.

“This place looked like a child fight club. It felt like one,” family attorney Russell Button told WFAA-TV.

“This kid was thrown around like a human rag doll by somebody that was supposed to protect him.”

Video footage cited in the Sept. 4 lawsuit filed in Tarrant County district court allegedly shows Johnson grabbing and shaking UH, shoving him away and later dragging him toward her son as the boy struggled to escape.

The suit alleges Johnson then swiped at UH’s leg while holding his wrist, causing both of his feet to leave the ground before he crashed onto the floor.

UH suffered bruises and scratches to his arms, headaches and pain to his backside, according to the complaint. His parents also claim he has since become anxious, clingy and prone to emotional outbursts, and ultimately stopped attending daycare.

Heather Harris told WFAA-TV that when she arrived at the daycare that day, she immediately sensed something was wrong.

“I knew from his cry and the look on his face that something had happened, and from that point on I said, ‘I need to see the cameras,'” she said.

Richard Harris told the station he was “mortified” after seeing the footage.

“The trust that I put in this daycare, they failed us,” he said.

The confrontation began after another child — Johnson’s son — hit UH in the back while teacher Jacqueline De Luna had her back turned, according to the suit.

After the boys stopped fighting, Johnson entered the classroom to relieve De Luna for a bathroom break, the complaint alleges.

Johnson’s son then pushed UH in the chest, and when UH raised his hands, Johnson lunged at him and grabbed his arm, according to the filing.

The lawsuit says De Luna later told state investigators that Johnson instructed her son to kick UH and tried to make him hit the child.

Johnson also allegedly had a history of yelling at and aggressively handling children before the April incident, according to statements from employees cited in the complaint.

Arka administrator Joyner Calvin allegedly told investigators she had heard Johnson yelling at children and said the issue had been addressed with her “a couple of times,” according to the lawsuit.

Another employee, Emma Rogers, allegedly told investigators she had seen Johnson grab children by their upper arms and roughly sit them in chairs, and said Johnson would “snap and start yelling at the children and handling them in an aggressive manner.”

Texas’ Health and Human Services Commission later cited the daycare over the April incident for improper discipline, prohibited punishment and failures involving employee judgment and intervention, according to the suit.

An employee at the daycare told WFAA-TV “no comment” when the station sought a response to the lawsuit and directed the reporter to email the daycare’s director.

The Post has sought comment from Johnson and the daycare center.