A public school district in Mississippi continues to operate predominately single-raced schools, according to the U.S. Department of Justice, which has filed a motion in federal court to order the district to develop an plan to integrate.

“It is intolerable for school districts to continue operating schools that retain their racial identity from the Jim Crow era,” Thomas E. Perez, Assistant Attorney General for the Civil Rights Division, said in a statement. “If school districts are not willing to work collaboratively to eradicate the vestiges of de jure segregated schools, we will ask the courts to take the steps necessary to ensure that students of all racial backgrounds have the opportunity to attend diverse, inclusive schools.”

But an attorney for the Cleveland, Miss. Public School District told the Associated Press that they have fulfilled their obligation to a 1969 desegregation order and often update the federal government on their attempts to integrate.

“Of our 10 schools, we have six that have a significant integrated population,” attorney Jamie Jacks said. “The district was hopeful they would see not only that we are a truly integrated system within the Mississippi Delta, but we’re a good school district. Our kids do well and get a great education.”

She said the district implemented a transfer program to bus Black students to historically White schools soon after the federal order came down more than 40 years ago.

During legalized segregation, schools on the west side of the railroad tracks in Cleveland, Miss., were White, while schools less than three miles away on the east side were Black.

The Justice Department alleges that students and teachers on the west side “maintain their character and reputation” as predominately White and the schools on the east were never integrated. The federal agency said their attempts to collaborate with the district to remedy the vestiges of segregation have been unsuccessful.

Of Cleveland’s 3,491 students, 68 percent are Black and 29 percent White, according to the AP.

Jacks insisted that one formerly White school and one historically Black school in the district have been integrated.

“Cleveland High School, which is the on the west side is 47 percent African-American; 50 percent white; 2 percent Hispanic and 1 percent Asian,” she told the AP. “Cleveland High used to be 100 percent white.”

Bell Academy, which used to be 97 percent Black, now has just an 80 percent Black population, she added.

It is unclear when the federal courts will rule on whether or not the school district is in violation of the 1969 desegregation order.

Last month, the Justice Department’s Civil Rights Division spearheaded a court-authorized integration strategy in another school district in Southern Mississippi, located in Leake County. The agency found that the area operated four predominately single-race schools and requested that two of the schools shutter while the remaining schools improve their quality of education and diversify their student and teacher pool.