The arrests were the culmination of an eight-month FBI investigation that took agents "deep into a hidden culture of hatred and violence," Acting U.S. Attorney Tom Beall said.

A complaint unsealed Friday charges Curtis Wayne Allen, 49; Patrick Eugene Stein, 47; and Gavin Wayne Wright, 49, with conspiring to use a weapon of mass destruction. Their first court appearance is Monday.

Prosecutors said the men don't yet have attorneys. Publicly listed phone numbers for the men couldn't immediately be found.