WASHINGTON (Reuters) -The U.S. Department of Justice announced on Tuesday that it had launched an investigation into Des Moines Public Schools in Iowa to determine whether the district engaged in race-based employment practices.

The Justice Department said in a letter to interim superintendent Matthew Smith that it was looking into whether Iowa's largest public school system had violated the Civil Rights Act of 1964 by engaging in what it described as a pattern or practice of discrimination based on race, color or national origin.

Title VII of the Civil Rights Act prohibits employment discrimination on the basis of race, religion, national origin, color and sex.

The DOJ pointed to a 2021 program at the district that outlined recruitment goals, including increased recruitment of teachers of color in kindergarten through fifth grade.

"DEI initiatives and race-based hiring preferences in our schools violate federal anti-discrimination laws and undermine educational priorities," Harmeet K. Dhillon, assistant attorney general at the department's Civil Rights Division, said in a statement.

"School districts must cease these unlawful programs and restore merit-based employment practices for the benefit of both students and employees."

The Des Moines Public Schools district confirmed it received the DOJ letter on Tuesday afternoon.

"We are reviewing their letter and will respond to them accordingly," spokesman Phil Roeder said.

Last week, U.S. immigration officials arrested Des Moines' public schools superintendent Ian Roberts, acting on what authorities said was a 2024 deportation order. Roberts, who remains detained, is originally from Guyana. Roberts is resigning from his post, said his attorney Alfredo Parrish in a Tuesday news conference.

The DOJ made no reference to Roberts in its announcement of Tuesday's probe.

U.S. President Donald Trump has issued a series of executive orders aimed at dismantling diversity, equity and inclusion programs since returning to the White House in January. His administration subsequently launched DEI-related probes into schools across the country. In May, the Justice Department formed a new unit focused on investigating DEI policies at universities.

The Department of Education has also outlined plans to investigate DEI policies in elementary and secondary schools. 

While Trump's administration and supporters argue that DEI unfairly discriminates against other Americans, including white people and men, civil rights advocates say DEI programs help address continued effects of historical and generational inequity and remove systemic barriers for groups affected by a legacy of racism, sexism and xenophobia.