Officials in east Mississippi operate a "school-to-prison pipeline" that incarcerates students for disciplinary infractions as minor as dress code violations with a policy that affects mostly black and disabled children, the U.S. Justice Department said Friday.

The Justice Department said police in the city of Meridian routinely arrest public school students without determining if there's probable cause when the school wants to press charges for a violation. Federal authorities say the students are then denied due process in youth court and on probation. The Justice Department did not outline specific allegations of wrongdoing against the school district in a letter to state and local authorities. Instead, it appears from the letter that the problems begin once a student is arrested.

Once arrested, the youth court puts the students on probation, sometimes without proper legal representation, according to the letter. If the students are on probation, future school violations could be considered a probation violation that requires them "to serve any suspensions from school incarcerated in the juvenile detention center," the department said.

That means if a student is on probation and then gets suspended for a minor infraction like "dress code violations, flatulence, profanity, and disrespect," the student could have to serve that suspension in the detention center.

"The students most severely affected by these practices are black children and children with disabilities in Meridian," the Justice Department said.

The Justice Department made the allegations in a letter to Mississippi's governor, attorney general and various officials in Meridian and Lauderdale County.

"These entities, working in conjunction, help to operate a school-to-prison pipeline that routinely and repeatedly incarcerates children for school disciplinary infractions," the letter said.

The department said if the matter isn't corrected soon it will sue the Lauderdale County Youth Court, the Meridian Police Department and the Mississippi Division of Youth Services, a division of the state Department of Human Services. The Division of Youth Services is involved the probation system.

"The systematic disregard for children's basic constitutional rights by agencies with a duty to protect and serve these children betrays the public trust," said Thomas E. Perez, Assistant Attorney General for the Civil Rights Division. "We hope to resolve the concerns outlined in our findings in a collaborative fashion, but we will not hesitate to take appropriate legal action if necessary."

The police department referred questions to a city spokesman, who didn't immediately return a call. The governor's office, the youth court and DHS didn't immediately comment on the letter. The school district superintendent didn't immediately respond to a message.

The letter said the findings are the result of an eight-month investigation. The letter also said that Lauderdale County Youth Court Judges Frank Coleman and Veldore "Vel" Young pledged to cooperate in the investigation, but "consistently denied DOJ access to information about the policies and practices" of the court and directed the city of Meridian to deny the department access to files concerning children.