Colorado authorities are investigating possible threats against state Supreme Court justices, Denver police have said, one week after the court's decision barring former U.S. President Donald Trump from the state's presidential primary ballot.

The Denver Police Department also said Tuesday that it was providing "extra patrols" around the homes of the justices, who ruled 4-3 on Dec. 19 that Trump should be disqualified under a little-known clause of the U.S. Constitution's 14th Amendment for engaging in insurrection.

Two nights later, Denver police officers were dispatched to the home of one of the justices in response to a call for service that police afterward described as an apparent "hoax report," adding that they were still investigating the incident.