After flagging tens of thousands of registered voters for citizenship reviews, the Texas secretary of state’s office is now telling counties that some of those voters don’t belong on the lists it sent out.

Officials in five large counties — Harris, Travis, Fort Bend, Collin and Williamson — told The Texas Tribune they had received calls Tuesday from the secretary of state’s office indicating that some of the voters whose citizenship status the state said counties should consider checking should not actually be on those lists.

The secretary of state’s office incorrectly included some voters who had submitted their voting registration applications at Texas Department of Public Safety offices, according to county officials. Now, the secretary of state is instructing counties to remove them from the list of flagged voters.

“We’re going to proceed very carefully,” said Douglas Ray, a special assistant county attorney in Harris County, where 29,822 voters were initially flagged by the state. A “substantial number” of them are now being marked as citizens, Ray said.

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It’s unclear at this point how many counties have received these calls. County officials said Tuesday they had not received anything in writing about the mistake. It's also unclear how many people will be removed from the original list of approximately 95,000 individuals flagged by the state. The secretary of state's office did not respond to questions Tuesday about how much this would reduce the initial count.

In a statement Tuesday, Sam Taylor, a spokesman for the secretary of state, said the state was providing counties with information as "part of the process of ensuring no eligible voters were impacted by any list maintenance activity."

"This is to ensure that any registered voters who provided proof of citizenship at the time they registered to vote will not be required to provide proof of citizenship as part of the counties’ examination," Taylor said.

Over the weekend and on Monday, counties started receiving lists of registered voters whom the state said provided DPS with some form of documentation, such as a green card or a work visa, that showed they were not citizens when they obtained driver's licenses or ID cards.

Most of the counties with the most registered voters in the state said they were holding off on sending “proof of citizenship” letters to the voters who were flagged. Just Galveston County officials said they were dropping some letters in the mail Monday, starting a 30-day countdown for voters to provide proof of citizenship such as a birth certificate, a U.S. passport or a certificate of naturalization. Voters who don't respond will have their voter registration canceled.

Galveston County officials did not respond to a request for comment Tuesday.

Elections administrators in Williamson County and Travis County said they received calls from the secretary of state’s office, too.

Chris Davis, Williamson County’s elections administrator, said the counties were now being instructed to consider certain voters on the list as citizens. Both Davis and Bruce Elfant, Travis County’s tax assessor-collector and voter registrar, said that would likely cause a “significant” drop in the number of registered voters flagged by the state. Williamson initially received a list of 2,033 individuals from the state. Travis was facing a list of 4,547 registered voters for review.

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John Oldham, elections administrator in Fort Bend, said he also received a call from the secretary of state's office indicating that some of the names on the initial list of 8,035 individuals it received from the state should not be there.

His office hadn’t determined how many voters would be removed from the list of flagged voters, but he noted officials had found two noncitizens on the rolls. In both of those cases, the individuals had indicated they were not citizens on their voter registration applications but were mistakenly added to the voter rolls, Oldham said.

“That happens,” Oldham said.

State officials announced they were sending the list in a press release from the secretary of state's office that emphasized the number of voters who had been flagged. Since then, top Republican officials, including President Donald Trump and Attorney General Ken Paxton, have pointed to the numbers to raise unsubstantiated claims of voter fraud. But election officials have pointed out that it’s possible that many of the individuals could have become naturalized citizens since they obtained their driver’s licenses or ID cards.

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At least one lawsuit has been filed against the state over its efforts to flag voters for citizenship checks. The League of United Latin American Citizens’ national and Texas arms are suing the state over what they say is an “election-related ‘witch hunt’” designed to intimidate legitimately registered voters by asking them to prove their citizenship.

Other civil rights groups have warned that the state’s recommended procedure for verifying voters’ citizenship status could violate federal law, and several are considering litigation against the state.

"Texans expect their government to do their due diligence before releasing incorrect and faulty data that could affect tens of thousands of people," said Beth Stevens, voting rights legal director with the Texas Civil Rights Project, one of the groups that issued the warning. "This confusion could have been avoided if the secretary and other state officials stopped their dangerous crusade to drum up support for their voter suppression agenda."