There were “unsubstantiated” bomb threats made to four locations in Navajo County, Arizona and state officials have “reason to believe” that the threats originated in Russia, Arizona Secretary of State Adrian Fontes said, CNN reports.

“We have no reason to believe that any of our voters or any of our polling places are in any sort of jeopardy,” Fontes, a Democrat, told at a media briefing.

“This is another, we believe, probing attack,” he said. “We also have reason to believe — although I won’t get into specifics — that this comes from one of our foreign enemies, namely Russia.”