GRAND JUNCTION – A Colorado county clerk posted claims of voter fraud without providing evidence and despite assurances from election officials nationwide that the November election was safe and secure.

Mesa County Clerk and Recorder Tina Peters tweeted on Sunday that ballots could be counted more than once and that software used in voting machines could be manipulated, The Daily Sentinel reported.

The tweet was done as a response to Republican U.S. Sen. Pat Toomey of Pennsylvania, who denounced his fellow party members in the Senate who plan to challenge the Electoral College certification on Wednesday.

“You would be wise to learn the Constitution that you swore to uphold and to protect us from enemies ‘foreign and domestic,’” Peters tweeted.

Eric Coomer, a Colorado-based Dominion Voting Systems executive, the Colorado Secretary of State’s Office, dozens of elections officials nationwide and former U.S. Attorney General William Barr have repeatedly said there has been no evidence of widespread voter fraud.

Neither Peters nor her staff responded to a request for comment from the Sentinel.

False allegations of voter manipulation and threats directed toward Coomer have forced the executive to go into hiding.

“I did not ‘rig,’ or influence the election, nor have I participated in any calls, demonstrations or other demonstrable activity related to any political party or social/justice group,” Coomer wrote in a Dec. 8 guest commentary in The Denver Post.