The Southern Poverty Law Center filed a formal complaint Wednesday with the U.S. Department of Education accusing a North Carolina school district of discriminating against Latino students.

Hispanic pupils do not "feel welcome" in the Durham Public Schools, the SPLC said last month in a letter to the school district, whose 32,566-member student body is around 20 percent Latino.

The DPS' "vague" and non-committal response to the April letter prompted the SPLC to approach federal authorities.

The Education Department is now investigating the allegations about Durham schools, SPLC's director for Educational Advocacy, Jerri Katzerman, told the media.

The SPLC, which is based in Montgomery, Alabama, says it is pursuing the matter on behalf of the Durham school district's more than 6,000 students with limited English proficiency and their families.

In one incident at Durham's Northern High School, a teacher slammed a Latino student against a wall and told the pupil: "go back to your own country," while another teacher at the same school uttered an ethnic slur against a Hispanic student, the SPLC said.

The district is also faulted for having only three qualified Spanish-language interpreters.

The DPS' legal counsel is reviewing the complaints, school district spokesperson Tahira Stalberte said.

Pilar Rocha, director of El Centro Hispano, Durham's largest immigrant organization, says "it's not surprising" that DPS is under investigation for discriminating against Latinos, given the large number of complaints she had heard from parents.