Updated

FBI interviews and surveillance of at least a dozen political activists in Kansas and Missouri prior to the Democratic National Convention (search) amounted to intimidation, contends the American Civil Liberties Union (search).

The FBI and activists said agents carried out the interviews while investigating potential attacks on news vehicles at the Democratic convention in Boston. Spokesmen for the bureau said the interviews are routine when authorities receive credible information involving potential violence, especially since the Sept. 11, 2001, terrorist attacks.

But the ACLU, which is representing three activists, contends the FBI was trying to intimidate political protesters under the cloak of counterterrorism.

"The overt nature of the surveillance was very intimidating and, I think, done with the intent of frightening them," said Denise Lieberman, legal director of the ACLU of Eastern Missouri.

Three activists from Missouri received subpoenas to appear before a grand jury for an investigation into domestic terrorism the day they planned to travel to Boston, ending their plans to protest, Lieberman said.

Also, four FBI cars followed the men for five days, she said.

Pete Krusing, a spokesman for the St. Louis bureau of the FBI, denied the interviews were aimed at discouraging protest.

"It's not just because they're a protester or they may be a protester," he said. "There has to be some indication that they have knowledge or they may have knowledge about some activity."

U.S. Attorney Jim Martin said he couldn't confirm there was a grand jury investigation or comment on a specific case.

In Kansas City, Nate Hoffman and Jeff Kinder, both 21 and students at the University of Missouri-Kansas City, said they were approached by FBI agents July 23.

Kinder said they asked him if he intended to do anything violent at the conventions and whether he heard of anyone planning violence. He said he didn't know anything — and still doesn't.

"Everybody I know is trying to build a mass movement, and you can't build a mass movement in America by blowing stuff up," he said.

Hoffman met agents in a Kansas City coffee house but refused to answer their questions without a lawyer. "They told me that in their experience that when somebody didn't want to talk to them that meant they probably had something to hide," he said.

The agents gave him a business card. Hoffman never called.

"You always hear that when you become politically active, you're put on some list. But it doesn't become real until you get a visit from the FBI," Hoffman said.

Jeff Lanza, a spokesman for the FBI in Kansas City, said he couldn't comment on whether agents had talked to Hoffman and Kinder but said the bureau had interviewed about a dozen people in the Kansas City area and Lawrence, Kan.

"Ultimately, we were looking for the people who wanted to carry (the attacks) out, but to do that, you have to talk to people who might have knowledge of the plan," Lanza said. He added that the bureau is no longer conducting interviews locally.