COLUMBUS, Ohio — Around 4,000 Ohioans may be on the brink of being illegally purged from state voting rolls, voting-rights advocates said Thursday.

Representatives of groups including the League of Women Voters and the NAACP called on Secretary of State Frank LaRose, the state’s top elections official, to delay a scheduled Sept. 6 purge of 235,000 voters from the rolls.

“While the Secretary of State has a duty to maintain the voter list, he also has a duty to protect the voting rights of every single Ohioan,” Mike Brickner, Ohio director for All Voting is Local, said during a Thursday news conference in Columbus. “But if we have reason to believe some people’s voting rights will be taken away from them unlawfully and in error, he has a duty to slow down this process.”

Jen Miller, executive director for the League of Women Voters of Ohio, said her organization is “Looking at all options” to stop the purge, including possible lawsuits or ballot initiatives.

In a statement, LaRose didn’t directly respond to the postponement request.

“We will continue to work with organizations and churches across the state to locate Ohioans who want to stay active, while also working with the General Assembly to improve the process we use for list maintenance in the future,” LaRose said.

Asked Thursday if the activists had shared their findings with the state office for review Thursday, officials in the secretary of state’s office said they had not.

Since taking office in January, LaRose, a Republican, has been trying to address concerns from voting-rights groups that have long criticized Ohio’s method of purging inactive voters. But he’s also moved forward with the purge, which the U.S. ​Supreme Court upheld in 2018 following years of litigation. The issue generally has broken down ​along partisan lines, with Republicans who have controlled state government in recent years and many elections officials defending the process as necessary maintenance, while Democrats and activists have said it results in voters being disenfranchised.

As part of LaRose’s outreach, he provided advocacy groups in early August with the names, addresses and voting history of 235,000 people whose names were on the purge list. In Ohio, voters are purged after failing to vote for six years, as well as failing to respond to postcards sent by the state to their address on file.

The voting-rights groups compared the 235,000 names to the state’s active voter list, as well as third-party voter databases. They found more than 4,000 people were on the purge list and the state active-voter list, they said Thursday. They also found around 17,500 people on the purge list voted somewhere in 2018.

The activists said they have not yet shared the information directly with the Secretary of State’s Office.

This is in addition to the 1,128 Franklin County residents LaRose’s staff found were improperly on the list following a review earlier this summer. Those residents hadn’t voted or responded to state mailings, but did sign a petition at some point, which under state law should keep them off the “inactive” list.

LaRose in February also ordered postcards to be sent to 264,516 voters on the preliminary purge list at a cost of about $130,000. State officials heard back from 540 voters.

The voting-rights activists said LaRose seems well-intentioned in his attempts to work with them, but said they continue to find new problems with the list of purged voters. They are working to find contact information for the 235,000 people, and plan to organize mass texts and phone banks to attempt to contact them before they are removed.

“While we do appreciate Secretary LaRose’s willingness to partner with the NAACP and other community groups, to reach out to 235,000 voters in a little more than a month is unrealistic,” said Tom Roberts, president of the NAACP Ohio Conference.

The Ohio Secretary of State’s Office has launched a website , www.ohiosos.gov/registrationreset, where voters can check the purge list to see if they appear there.

Anyone who wants to update their voter registration can contact their local county board of elections or visit OhioSoS.gov/update.