The FBI is working with law enforcement officials in Colorado in the wake of threats made against state Supreme Court justices who ruled last week to remove Donald Trump from the state’s 2024 presidential ballot.

“The FBI is aware of the situation and working with local law enforcement,” FBI Public Affairs Officer Vikki Migoya said in a statement provided to CNN on Monday. “We will vigorously pursue investigations of any threat or use of violence committed by someone who uses extremist views to justify their actions regardless of motivation.”

A spokesperson for the Colorado Judicial Branch would not comment on reports of threats to the justices, and a message left with the Denver Police Department was not immediately returned Monday afternoon. Master Trooper Gary Cutler, a spokesman for the Colorado State Patrol, said any threats against judges would be handled by local authorities.

In addition to the federal response, state and local law enforcement officials and non-government research groups have been monitoring rhetoric on extremist online forums for signs it might translate to tangible threats to public officials.