The Maricopa County Sheriff's Office told a local ABC affiliate that it is investigating several individuals who were watching a Mesa voting location on Friday. The department confirmed that two individuals at the site were armed.

A clip posted to social media by ABC reporter Nicole Grigg shows two masked people dressed in tactical gear observing the ballot drop box.

"This is obviously totally incompatible with liberal democracy and an open society," MSNBC's Chris Hayes wrote in response to the video.