A progressive advocacy group is launching an advertising campaign accusing Indiana Gov. Mike Pence, who also is the Republican vice-presidential nominee, of sanctioning voter suppression after state police raided the offices of a voter registration program aimed at signing up African-Americans.

Patriot Majority USA will place the ads on black-oriented radio stations and in print and online with black newspapers throughout the state starting Saturday, said the group's director, Craig Varoga. Patriot Majority is affiliated with the Senate Majority PAC, a super PAC that supports Democratic candidates.

On Oct. 4, one week before the state's deadline to register to vote, state police raided the Indianapolis office of the Indiana Voter Registration Project, seizing computers, cellphones and records. The state police launched an investigation in late August after elections officials in Hendricks County, a suburb of Indianapolis, alerted authorities to some applications that seemed amiss. A spokesman for the state police told local news media that "at least 10" applications were confirmed to be fraudulent.

Varoga estimates that 45,000 people, most of them African-Americans, might not be able to vote on Nov. 8 because their applications were seized during the raid. The group has asked the Justice Department to investigate and the Lawyers' Committee for Civil Rights Under Law, an advocate for voting rights, sent a letter to Indiana Secretary of State Connie Lawson asking her to take steps to ensure that eligible voters who signed up through the voter registration drive will not be disenfranchised.

Spokespersons for Pence, Lawson and the state police could not be reached late Friday. Pence made reference to the police investigation during a campaign stop in Iowa on Tuesday.

Patriot Majority's one-minute radio ad opens with a wailing siren and a male announcer referencing the raid: "Indiana state police recently shut down our state's largest voter registration program. This police raid was under the leadership of Republican Gov. Mike Pence. Now 45,000 citizens, almost all African-Americans, could lose the right to vote."

The ad also includes voices of some of the workers at the office. "They singled out one African-American male, put him in handcuffs," says one woman. "They lined us up against the wall, treated us like criminals," says another woman. The group also lays out its complaint on a web page, dontbetrayindiana.com.

Two days after the raid, the Indiana Voter Registration Project said it had asked the Justice Department to look into the state's investigation. The Indiana State Police then announced that the investigation had expanded from nine to 56 of the state's 92 counties.

Varoga said the Indiana Voter Registration Project was launched in May and had hoped to sign up 50,000 voters by the Oct. 11 deadline. He thinks they would have reached the goal had the state police not shut down the program. Patriot Majority has conducted voter registration drives in 12 other states Varoga said, and "in no other state have we seen the state police brought in to harass canvassers, to go homes of canvassers and threaten them with arrest and demanding they take polygraph tests."

Indiana generally leans red, although Barack Obama won the state by just over 1 percent in 2008, the first Democrat to take the Hoosier State since 1964. But he lost the state by 11 percentage points to Mitt Romney in 2012. The RealClearPolitics average of polls for the state show Republican presidential nominee Donald Trump leading Democratic nominee Hillary Clinton by 4.5 percent.

Democrats are hoping that former senator Evan Bayh can win back his old seat, which is being vacated by retiring Republican Sen. Daniel Coats. Bayh is in a tight race with Republican Rep. Todd C. Young.

The voter registration applications flagged by election officials in Marion and Hendricks counties "contained minor inaccuracies like missing Zip codes and area codes," Varoga said. "Based on the fact that they found (problems in) 10 forms out of tens of thousands ... to launch a statewide investigation into a voter registration program is a political agenda. Whether or not it originated in the governor's office, it clearly has the sanction of the governor and the secretary of state," he said.

A news release from the state police also stated some of "the forms had missing, incomplete and incorrect information at the time they were submitted by representatives of an organization called the Indiana Voter Registration Project." That same day, the secretary of state's office said the group "has turned in forged voter registration applications. The group was altering already registered voter's information. The group would change the voter's address to an address not associated with the voter without the voter's knowledge."

"Election integrity and security is a top priority," Secretary of State Lawson said in the news release. "We are working with the state police to ensure this matter is addressed quickly."

Officials urged voters to go to a state website or check with their county office to make sure they were properly registered before the deadline.

At the Iowa campaign event, Pence told the crowd, "In the state of Indiana, we have a pretty vigorous investigation into voter fraud going on right now. And I encourage you here in Iowa, let's be sure that our state officials are upholding the principle of 'one person, one vote' and the best antidote to that is to be involved in the election process. If you are concerned about voter integrity and you haven't signed up to be a poll watcher, to volunteer at a polling place to be a part of the integrity of that process, then you need to do it."

Pence's comments lacked the conspiratorial tone of those made by running mate Donald Trump, who warned his supporters that the presidential election might be stolen from him and has said it might be necessary for them to go to "certain areas" and keep an eye out for people trying to "vote five times."

In recent years, Republican governors and legislatures, citing concerns about voter fraud, have enacted numerous laws requiring specific forms of identification, curbing early voting periods and requiring additional verification for people trying to register to vote. Such changes accelerated after the Supreme Court struck down a section of the 1965 Voting Rights Act that required states to seek prior approval from the Justice Department. But legal scholars and studies have found that in-person voter fraud is very rare and such laws adversely affect turnout among minorities and younger voters.