The Montgomery-based center filed suit July 25 against the Imperial Klans of America in Kentucky's Meade County Circuit Court over the beating of a 16-year-old boy of Panamanian descent.

"The latest case against the IKA promises to be as dangerous as anything we've faced," SPLC co-founder Morris Dees stated in an e-mail Monday. "We won't back down from these threats, but we'll have to increase our security to ensure the safety of our staff."

The Montgomery Advertiser, which reported the increased security Tuesday, said there have been almost a dozen threats in relation to the suit.

Although SPLC security director Tom Brinkman said it's company policy not to disclose details about security measures, he confirmed that additional measures have been taken, the newspaper said.

The suit contends that two Klansmen on savagely beat Jordan Gruver, 16, at a Kentucky county fair in July 2006.

Jarred R. Hensley, 24, of Cincinnati and Andrew R. Watkins, 26, of Louisville are serving three-year prison terms after pleading guilty to second-degree assault in the beating. The center sued them for their actions in late February, with the July 25 filing adding the IKA and three other individuals as defendants.

The IKA's Web site lists its mailing address in Dawson Springs, Ky., and its Imperial Wizard as Ron Edwards, who is named as a defendant in the suit.

Edwards said in an e-mail to The Associated Press on Tuesday afternoon that the organization didn't find out about the incident in Kentucky until two weeks after it happened.

"They attended this fair on their own, without 'official' IKA sanction," he said of the accused Klansmen. "The IKA should not be held financially responsible for the actions of others."

"We consider this civil lawsuit as a means of attempting to 'silence' us and thus make others 'afraid' to state similar beliefs, for fear of persecution," he said.