The North Carolina chapter of the NAACP, along with a handful of individual voters, sued the state’s elections board and three county elections boards Monday over an alleged voter purge that it claims disproportionately affected African Americans.

Some 4,500 voters’ ability to vote is in limbo, the complaint alleges, due to the efforts by a few individuals to challenge their registrations. The NAACP-NC accused state and local officials of violating the National Voter Registration Act and the federal Voting Rights Act in their handling of the challenged voters. The lawsuit was filed in the U.S. District Court for the Middle District of North Carolina.

“The Tar Heel state is ground zero in the intentional, surgical efforts by Republicans to suppress the voice of voters,” NAACP-NC President Rev. William Barber II said in a statement announcing the lawsuit. “The NAACP is defending rights of all North Carolinians to participate in this election. We’re taking this emergency step to make sure not a single voters’ voice is unlawfully taken away. This is our Selma and we will not back down and allow this suppression to continue.”

In one of the counties, Beaufort County, black voters make up 65 percent of the challenges even though the county is 26 percent African American, according to the complaint. The registrations of 138 voters were challenged based on a mailing campaign sent by one of the challengers, Ricky Radcliffe, when he was running for mayor in 2015, according to the lawsuit. The list of challenged voters was made up of individuals who were supposedly sent the mailers and they were returned as undeliverable, the complaint said.

In Moore County, 400 voters’ registrations were challenged in a similar fashion by a single individual, N. Carol Wheeldon, according to the lawsuit. Her mailers said explicitly “DO NOT FORWARD,” the complaint said. Undeliverable mailers also led to nearly 4,000 voters being put on a challenged list in Cumberland County, the lawsuit alleged, and the county board of elections sought to move forward with the process to remove about 3,500 of them from the rolls.

(As the Nation noted, the scheme resembles the tactic that New Jersey Republicans used in the 1980s which led to the Republican National Committee being put under a consent decree limiting its activity at polling places.)

After an initial hearing, during which a person challenging a voter registration puts forward evidence to back the challenge, elections officials are required to notify the voter of a potential change to their registration status and request their presence at a second hearing with the local elections board, according to the lawsuit. Many of the challenged voters said they received no such notification, according to the filing. Some only found out their registrations were being challenged because acquaintances saw their name on the challenged list, the complaint said.

In the cases highlighted by the NAACP lawsuit, oftentimes, the voters whose registrations were put on the challenge lists had not moved out of the county where they are registered, had voted in past elections and intended to vote in November’s election.

This process, the NAACP alleged, violates the National Voter Registration Act, which outlines a protocol for removing voters from the poll books if the voters themselves say in writing they are changing their residence, or if they fail to vote in two general elections cycles after receiving a notice inquiring about their registration. The law also bars a systematic removal of voters within 90 days of an election. The alleged purge happened at hearings within the last three months, according to the lawsuit.

While North Carolina has state laws allowing for voter registrations to be challenged, the NAACP-NC nonetheless accuses elections officials of violating the NVRA in the alleged purges highlighted in the lawsuit. The NAACP-NC wrote a letter to the state elections board raising these concerns earlier this month, according to the suit, but the state responded arguing that it in its opinion, it was acting in accordance with the federal law.

Monday’s filing also alleges a violation of the Voting Rights Act, given the removals’ disparate impact on black voters.

The NAACP is asking for the court to halt the removal process, to restore the registrations of those highlighted in the lawsuit and also to see to it that the affected voters do not face any same-day challenges to their registrations at polling places on Election Day.

The lawsuit comes after a number of voting restrictions in a state law were struck down earlier this year as intentionally discriminatory by a federal appeals court. Civil rights groups have also raised concerns about the efforts by some local officials to limit early voting hours, which are used disproportionally by black voters.

Read the complaint below: