COLUMBUS, Ohio (AP) — Voting rights activists say about 4,000 Ohio residents are at risk of being illegally removed from state voting rolls, a figure questioned by the state’s elections chief.

In a letter to Secretary of State Frank LaRose, representatives of the League of Women Voters Ohio, the NAACP and other groups requested that he pause the process that will remove 235,000 voters from the rolls Sept. 6.

The groups made their plea Thursday after looking at lists compiled by 88 county boards of election and released by LaRose in June.

Executive Director Jen Miller said the League of Women Voters is exploring all options to stop what she calls a “purge” of eligible voters, including lawsuits or ballot initiatives.

LaRose, a Republican, had requested help from her organization and other community groups to locate voters whose registrations were at risk. Churches, elected officials, and voting rights groups were among those who asked for the list.

LaRose is continuing Ohio’s stringent series of warnings that start after a voter’s failure to participate in election activity from a given address for two years. The U.S. Supreme Court upheld the procedure last year.

Mike Brickner, the Ohio director of All Voting is Local, called for a statewide audit of the purge list by the Secretary of State.

The activists said that while LaRose means well in his attempts to work alongside community and grassroots organizations, they continue to find new problems with the process.

The office said this appears to be the first time a secretary of state in Ohio has requested the full inactive voter list from all counties considering registration cancellations. Late Thursday, the League provided LaRose with its data, which is being cross-checked against the original information from the counties.

“The office is confident that at least some are voters that have chosen to re-activate their registration, but is still conducting a comprehensive review of the data,” said spokesman Jon Keeling.