HOUSTON — A group of students from a historically black university have filed a lawsuit alleging a southeast Texas county is suppressing the voting rights of its black residents.

In a lawsuit filed in federal court in Houston on Monday, five Prairie View A&M University students allege Waller County election officials are violating the civil rights of black students and residents in Prairie View — which is predominantly African-American — by not providing any early voting locations on campus or anywhere in the city during the first week of early voting, which started Monday.

In the second week of early voting, the county is providing five days in Prairie View, but two of them are off-campus and at a site that is not easily accessible to many students who lack transportation, according to the lawsuit.

Prairie View is located about 50 miles northwest of Houston. The historically black university, which has about 8,400 full and part-time students, represents a significant voting bloc in Waller County.

The NAACP Legal Defense and Educational Fund, which filed the lawsuit on behalf of the students, says that by comparison, in the nearby majority-white city of Waller, voters have two locations to vote during the first week and overall 11 days of early voting. The group says the county's actions violate the Voting Rights Act and the U.S. Constitution.

"Since at least the early 1970s, Waller County has consistently tried to limit the political power of black voters in the city of Prairie View and at Prairie View A&M specifically by undermining their right to vote," said Leah Aden, the legal defense fund's deputy director of litigation.

Waller County District Attorney Elton Mathis didn't immediately return a phone call seeking comment Tuesday.

The lawsuit is asking for the county to extend the hours and days of early voting on the Prairie View campus.

The lawsuit comes after Democrats earlier this month had complained officials might block students from voting because of issues over addresses they used to register to vote.

Texas Secretary of State Rolando Pablos, along with Waller County officials and the heads of the county's Democratic and Republican parties later issued a statement saying no students will be "impeded, hampered, or otherwise delayed" in voting.

Waller County has a long history of voting and race being a contentious issue.

A case that made it to the U.S. Supreme Court in 1979 ended the county's practice of requiring students to fill out residency questionnaires in order to register to vote.

In 2003, former Waller County District Attorney Oliver Kitzman challenged the voting rights of Prairie View A&M students, arguing that the students did not meet residency requirements. The Texas Attorney General's Office later ruled the students do have the legal right to vote locally.

In 2008, the U.S. Justice Department entered into a consent decree with Waller County to resolve a lawsuit and eliminate invalid registration practices primarily affecting students at the university.