Thursday, April 1, 2010 | 3:48 p.m.
The FBI confirmed today that it sent an advisory to Nevada and other states notifying authorities of an extremist group's demand to remove governors from office, but said federal officials did not believe the group was an "immediate or credible" threat of violence.
Stricter security measures were put in place in the Nevada Capitol this week after police received a letter addressed to Gov. Jim Gibbons, telling him to resign his office. It made a reference to "commandeering" the office if Gibbons declined.
"The FBI and Department of Homeland Security are not aware of any immediate or credible threats of violence as part of this group's plan," said FBI special agent Joseph Dickey.
Dickey described the group behind the letter as a "sovereign citizen extremist group." He said individuals in the group reject all forms of government authority - paying taxes and obeying state and federal laws.
Gail Powell, spokeswoman for the Nevada Department of Public Safety, said security at the Capitol will continue at its current, higher level.
A source said the group that sent the letter identified themselves as Guardians of the Free Republics. According to the group's Web site , it advocates a "bold achievable strategy for behind-the-scenes peaceful reconstruction of the de jure institutions of government without controversy, violence or civil war."