MONTGOMERY, Ala. (AP) — A civil rights organization is asking Alabama's secretary of state to restore hundreds of thousands of people to active voter status after what the group described as widespread confusion in election day.

In a Friday letter to Alabama Secretary of State John Merrill, the Southern Poverty Law Center said it believes large numbers of people were incorrectly moved to inactive voting status during an update of rolls. Merrill responded that his office followed the law.

The secretary of state's office said 340,162 people were put on inactive voter status in the required update of voting rolls.

"What we are worried about is people have been purged from rolls and then may not, for one reason or another, end up being able to cast a ballot," Cohen told The Associated Press. The letter said the process used by the secretary of state is deeply flawed."

The letter gave incidents of people who were told they were inactive when they went to vote in this week's U.S. Senate primary, including an SPLC employee.

The employee had voted at the same location for 13 years, but registrars said they had her 2005 address listed, according to the letter. Inactive voters can vote, but must update registration information first. Merrill said many voters might be discouraged from voting, because they don't have time to pursue the matter.

The letter told Merrill that with the looming U.S. Senate primary runoff and general election it is "imperative you take immediate corrective action to return inactive voters to the active voting list."

Merrill on Friday said his office followed the law.

Merrill said people were placed on inactive status after a mailed registration card was returned as undeliverable and they did not receive, or respond to, a second forwarded postcard requesting that they update their address.

"What this process does is establish procedures, compliant with federal and state law, to provide voters ample opportunity to verify or update their voter registration information," Merrill wrote in a written response.