Law enforcement officers on Thursday denounced "Dateline NBC" 's reporting tactics at the Martinsville Speedway last weekend, calling them outrageous, amateurish and dangerous to fans and security staff.

Authorities also questioned the show's decision to visit a NASCAR race to test anti-Muslim sentiment in the United States.

"They were deciding that people who go to NASCAR races are probably less tolerant than other folks, so let's see what we can do to provoke them into doing something," said Kevin Foust, supervisory agent for the FBI in Roanoke.

But "Dateline" spokeswoman Jenny Tartikoff said in a statement Thursday that the race was just one stop in the program's research for the story, which is in its infancy.

"We can assure you that what we broadcast, if anything, will be fair and accurate," she wrote.

According to the Associated Press, NBC confirmed to NASCAR that it sent "Muslim-looking men" and a camera crew to the race to film fans' reactions. Tartikoff said "Dateline" is investigating reports of increasing anti-Muslim sentiment in the country and wanted to look at large public gatherings such as sporting events.

Henry County Sheriff's Maj. Kimmy Nester said he worked security at the race and witnessed two men and a woman who appeared to be of Middle Eastern descent. The trio were dressed in robes and were followed closely by three other people. The second group included a Middle Eastern woman wearing jeans and a T-shirt and two white men also dressed in Western clothing, Nester said.

Foust, who was not at the race but reviewed agents' reports, said one of the men was carrying a camera in a bag. He said it was the camera crew that made the group suspicious to security, not the fact that they appeared to be Muslims.

At 5 p.m. Saturday, the three people dressed in robes laid out prayer rugs by the main speedway office and knelt to pray, Foust said.

"Suppose somebody said, 'I don't want to see Muslims praying out in the open, I'm going to go over there and hurt them in some way,' " Foust said.

He said security kept an eye on the group for that reason. Law enforcement did not approach them or ask them to leave because they weren't breaking any rules or hurting anybody, he added.

But Foust questioned what would have happened if someone had picked a fight with the crew or attacked them, saying it placed the "Dateline" group, NASCAR fans and security guards at risk.

In addition, authorities said, the incident wasted time they could have spent looking for legitimate threats at the race.

"We have enough on our plate on a given day without someone introducing something that's false and bogus into an environment that has the potential for many, many things to go wrong," Nester said.

Bob Steele, a journalism ethicist with the Poynter Institute in Florida, said he does not doubt that prejudice exists against Muslims in America, and he hesitates to declare that "Dateline" acted inappropriately.

"I'm not willing to paint a broad-brushed 'wrong' sign over what NBC did," he said. "I think it's important that they justify their modus operandi."

Some questions he would ask "Dateline," he said, were:

n To what degree do they have hard evidence there is a real problem?

n Is the situation they created realistic?

n Are bystanders who may end up part of the report going to be treated fairly?

n Is "Dateline" making sure it is not putting testers or innocent people at risk with the experiment?

"It should not be a fishing expedition," Steele said. "They should have some proof that there is a journalistic purpose for going to, for instance, a NASCAR race or a golf course or a dental office or anyplace else they would choose. They shouldn't just guess or presume that there would be problems."

Ibrahim Hamidullah, imam at the Clarence Sabree Islamic Center in Roanoke, said he would not have taken part in NBC's experiment.

"We don't pray for attention," he said. "We're praying for God, we're doing things to please God. We shouldn't be doing things for attention."

He also questioned having the volunteers dress in clothes usually associated with Islam.

"Muslims dress like anybody else," he said. "That's not an Islamic dress code."

But Rabiah Ahmed said she had no problem with NBC's project.

"I'm not offended by their stereotypical depiction of a Muslim because I can see they would have to make the Muslims be visible Muslims in order for their experiment to work," said Ahmed, a spokeswoman for the Washington, D.C.-based Council on American Islamic Relations, an advocacy group.

"I find these types of social experiments to be very interesting," she said.

Martinsville Speedway spokesman Mike Smith, who has criticized the experiment, said that at least it proved that security is tight and race fans are a tolerant bunch.

Nester and Foust agreed.

"I saw nobody treat them any different than anyone else," Nester said. "If they believed they were surprising anybody that they were there among us, that was not the case."

Ahmed added that the NBC project might help dispel notions that Muslims might have about race fans.

"That might open Muslim eyes about their neighbors as well," she said.

Staff writer David Harrison contributed to this report.