(teleSUR) Protesters said that at least six people were bitten by security dogs, whose handlers were not licensed to work in North Dakota.

Private security guards who used attack dogs to break up groups of peaceful North Dakota pipeline protesters were not licensed and could face charges, the Morton County sheriff’s office announced Wednesday.

The report by the sheriff’s office said that seven of the dog handlers who were present at the Standing Rock Sioux camp on Sept. 3 were not licensed for security work in North Dakota.

The sheriff’s office passed on the investigation to prosecutors who are reviewing its details and the guards in question face possible misdemeanor charges.

“I was surprised that a company as big as what this pipeline company is. It would have security people working in the state, that came from other states,” said Capt. Jay Gruebele.

Officials from the security company told the sheriff’s office that they did not intend to use the dogs for security work, but “the dogs were deployed as a method of trying to keep the protesters under control.”

Private security guards were seen using pepper spray and dogs to attack peaceful, mostly Native American land protesters. A number of protesters were bitten and one of the dogs was shown with blood dripping from its nose and mouth. Protesters said that six people were bitten and 12 pepper sprayed.

A live video of the incident was filmed by Democracy Now!, and host Amy Goodman was charged for “rioting” over the coverage, but the charges were eventually dropped by a North Dakota state judge. The video has been viewed by more than 14 million people.

Police and private security have been more aggressively breaking up and arresting peaceful protests of late. After a series of clashes between protesters and law enforcement over the weekend, 126 protesters were arrested, with the Morton County Sheriff’s office admitting to using of tear gas.

In late September up to 21 people were arrested during a prayer service  with North Dakota police using shotguns, assault rifles and armored vehicles in the military style assault.

Indigenous and environmental activists say the US$3.8 billion pipeline will continue to ruin sacred burial grounds and pollute local water supplies. While construction has been stopped along small sections, protesters have vowed to continue fighting the project until it is fully shut down.

This post originally ran on teleSUR.