The older sister said the fight broke out after her younger sister refused to follow her instructions, KDFW-TV in Dallas/Fort Worth reported Tuesday.

"She pushed me, so I just walked away from it," the 13-year-old said. "The third time she pushed me, we just started fighting."

The girls, who were visiting family in Flower Mound with their mother, returned to the family home with a police officer in tow.

"'This is criminal, and one of them is going to have to go to jail and it's probably going to have to be your younger one because she was the aggressor,'" their mother quoted the officer as saying. "And I said, 'Are you kidding me?' and he said, 'No, no.'"

Lt. Clay Pierce of the Flower Mound Police said it was being treated as a case of family violence. The girl was charged with Class A misdemeanor assault.

"By state law we are required to take action and what we did, we detained the youngest one," he said.

"Both of them had some injuries. The one showed more serious injuries, so the other one was detained."

The case has been turned over to the Denton County district attorney for further review.

The girls' names are not being reported by UPI because they are juveniles.

                             UPDATE:

 The girls have been identified as Reagan Green, 10 and 13-year-old Desiree Green.