A threatening e-mail sent to the White House from Carson City was being investigated by federal and state authorities Friday.
The e-mail was sent Dec. 31 and threatened an individual, state Homeland Security Adviser Jerry Bussell said.
"There were no specific actionable threats that were made against Las Vegas or Nevada during the elevated alert level," Bussell said. "We get things like this e-mail, and you have to take a look at them."
The nation's terror alert level was raised Dec. 21, and cities including Las Vegas increased security for holiday celebrations and large gatherings. The level was lowered Jan. 9.
The FBI and state Department of Public Safety were investigating the e-mail threat. Text of the e-mail was not disclosed, but Gov. Kenny Guinn's spokesman Greg Bortolin said Las Vegas and Carson City were mentioned.
"It was directed at state government," Bortolin said.
Word of the e-mail came Thursday when Guinn referred to it during a question-and-answer session after a speech to the Las Vegas chapter of the National Association of Industrial and Office Properties.
Guinn initially said a small Nevada town had received the most credible terrorist threat during the nation's heightened state of alert. Later he revised his remarks to say even small towns had to be vigilant.
Guinn said the threat came from within the United States and was not linked to the terrorist group al-Qaida. Guinn said there are threats of more "Timothy McVeighs."
McVeigh was convicted and executed for the 1995 bombing of the Oklahoma City federal building that killed 168 people.
Bussell and the FBI said there no specific threat directed against Nevada or any of its cities.
"I don't know of any threats to any small towns, any big towns or any towns," FBI Special Agent Todd Palmer told the Las Vegas Sun, which first reported Guinn's remarks.