The Southern Poverty Law Center on Monday advised Montgomery County voters to verify which district they are in after a postcard was mailed out that incorrectly identified voters living in the newly drawn Second Congressional District as residing in the Seventh Congressional District.

SPLC co-founder Joe Levin was among those who received the postcard, the organization said, the organization said.

The SPLC blamed the mistake, which the group said appeared on a postcard mailed by the Montgomery County Board of Registrars, on the Alabama Secretary of State’s Office.

The organization said the registrars’ information is based off of the secretary of state’s voter file.

“Alabama voters deserve better from our leaders and accountability — Secretary [Wes] Allen needs to own up to this mistake,”Tafeni English-Relf, director of the SPLC’s Alabama state office, said in a statement. “I encourage every Alabama voter to double-check their congressional district and other election information as soon as possible.”

An official with the Secretary of State’s Office told AL.com the office is not responsible for the erroneous information.

“The information in the statewide voter file is inputted at the county level. The Secretary of State simply maintains the database,” said Laney Rawls. “If the information in the file was incorrect, it would have been inputted incorrectly by the county, not the Secretary of State’s office.”

Montgomery County Director of Elections Alexandria Stephens could not immediately be reached for comment.

To find out which districts they live in, voters can go to https://myinfo.alabamavotes.gov/voterview.

The SPLC said it learned of the mistake over the weekend and that the postcard was mailed about two weeks ago.

While the organization said it did not know how many voters received the erroneous postcards, “it appears that 5,604 voters were mislabeled in the voter file as being in the 7th Congressional District, instead of the newly formed 2nd District,” adding that 4,513 of those voters are Black.

“This is more than a misstep. Providing erroneous information to thousands of voters on the eve of a hotly contested primary election could very well impact the turnout and the results of the election, for both Republicans and Democrats,” said Bradley Heard, the SPLC’s deputy legal director for democracy.

“There needs to be an immediate audit and public accounting from Secretary Wes Allen’s office on the scope of the problem.”

Tuesday’s primary in the new Second Congressional District will be the most closely watched contest in Alabama.

A federal court approved a map redrawing the district in October, changing it from a safe Republican district to one where voters could elect the second Democrat and second Black representative in Alabama’s seven-member Congressional delegation.