MADISON, Wis. -

A video posted to the Internet shows activists confronting workers at a mining site in northwestern Wisconsin.

The video shows the activists approaching a Gogebic Taconite work site, yelling at the workers and telling them to leave the land. The activists also take video of the equipment and activities at the site.

The mining company is currently conducting tests at the Penokee Hills site for a possible mining operation.

Frank Koehn with the Penokee Hills Education Project, a group opposed to the mine, told News 3 he believes the incident occurred June 11. The video appears to show the incident that led to criminal charges against a demonstrator from Stevens Point. Mining equipment was damaged and a cellphone and camera were taken.

Gogebic Taconite hired guards after the incident.

Koehn said he does not condone the behavior that went on in the video and said he believes it was an isolated incident.

"I would not have allowed that to go on," Koehn said. "I think some people went out and one thing led to another, and there was a confrontation."

A worker at the Penokee Hills education and gathering camp, Andrea Ladenthin, told News 3 she obtained the video, but that she was not part of the group that visited the work site. She said she found the video in her camping gear. She said she felt it was her duty to share it.

Ladenthin said she doesn't condone what's shown in the video.

"I would not go that far. I think it’s a group of young individuals who think they know everything," she said.

Iron County Sheriff Tony Furyk told News 3 they're reviewing the video to determine the identity of the other people involved in the incident. The district attorney also has the video.

The video surfaced after the mining company announced Wednesday that it would suspend its use of armed guards at the mining site. The company said it suspended its use of Arizona-based Bulletproof Securities because it is not licensed in Wisconsin.

Furyk said another security team arrived Thursday.

The use of Bulletproof Securities was criticized by Sen. Bob Jauch, D-Poplar, who said he was appalled and horrified by the images of the guards and angry over the fact that they've been in the state illegally.

Bill Williams, Gogebic Taconite president, said the security company applied for the appropriate Wisconsin license but had not yet had its application approved.

Warning: The video contains graphic language.