Authorities say they're investigating after a list containing the personal information of several Minnesota police officers was made public.

The list was first reported by the news site Vocativ, which says its analysts discovered the list of 36 officers on an encrypted application. Vocativ called it a "kill list" and says it was posted by a group of hackers who support the Islamic State group.

FBI spokesman Kyle Loven says the list contains names of officers from around Minnesota and neighboring states. He said Tuesday the FBI is trying to determine a motive and find out who is responsible.

Loven would not confirm where the list was posted, how many officers were on the list and whether it was a "kill list," saying the FBI was investigating the facts.