The FBI has issued an alert to police departments across the country warning that anarchist groups are planning a “Halloween revolt” plot aimed at attacking local police during Halloween week.

The New York Post learned the FBI said that a group called the “National Liberation Militia” is planning to don costumes and then to causes disturbances that will draw police to the scene. Then, the FBI warns, the groups intend to ambush the responding officers.

The FBI has refused to comment further on the threat, only saying that the alert sent to police agencies across the country was part of a “continuous dialogue” with police departments.

Los Angeles police have determined that the warning is not based on a “credible threat” in their city. New York police also reported that there is no known threat to the Big Apple.

NBC noted that the FBI said that this “National Liberation Militia” is a group on their watch list, but also pointed out that little can be found about the group online. A look online shows a black power group called the New Black Liberation Militia, but no mention of the group revealed by the FBI this week. There is also no mention of the National Liberation Militia on the FBI’s website.

Still, it is not uncommon for first responders to be ambushed upon arriving at the scene of a fire or a crime.

Last November, for instance, in Leon County, Florida, police and firemen were fired upon when they responded to a house fire. One sheriff’s deputy was shot and killed, and a second deputy was also shot in the incident. The shooter was eventually killed by Tallahassee police who also responded to the scene.

Black Lives Matter protesters have also interfered with first responders. Earlier this year a rioter in Baltimore was arrested after cutting a fire hose when firemen arrived to put out the flames of a CVS pharmacy set ablaze by protesters. Also, during protests in New York in December of last year, several protesters tried to stop police from arresting a CUNY professor for throwing a trash can and inciting a riot.

Follow Warner Todd Huston on Twitter @warnerthuston or email the author at igcolonel@hotmail.com