FARGO, N.D. -

The FBI says it is investigating anonymous online threats made against political leaders, law enforcement and Dakota Access pipeline workers.

YouTube videos posted by "Anonymous Agents" include threats against President Barack Obama, North Dakota Gov. Jack Dalrymple, National Guard soldiers, law enforcement officers, Energy Transfer Partner executives and construction workers on the $3.8 billion, four-state pipeline.

FBI Special Agent Kyle Loven says the FBI is sharing information with state and local authorities. He says law enforcement does not want the situation to "become any more volatile than it already has."

Pipeline protests have at times become violent, and dozens have been arrested in the last few months.

U.S. Sen. Heidi Heitkamp from North Dakota condemned the threats and called on the U.S. Department of Justice to investigate the videos' "source and credibility."