ANN ARBOR -- Police are investigating threats on made on social media against Jim Harbaugh.

The University of Michigan Police Department launched an investigation Monday night into social media threats apparently aimed at the Michigan football coach, Melissa Overton, deputy chief and department spokeswoman confirmed to MLive on Tuesday.

Overton would not go into detail of the those threats, citing an ongoing investigation. No one has been arrested or charged.

A published report by Deadspin on Tuesday showed a series of cryptic, expletive-filled messages -- captured via screenshot and later posted on Reddit -- from the Twitter account that purportedly belongs to someone who has played for Michigan football.

Among the tweets are, "Michigan is open carry. Let's not forget. Not your friend." and "They sent someone to my crib before. I was nice enough to call the cops next time I'm calling the morgue. I'm talking with facts"

Another tweet claims the the author "was suspended for going to take care of my family" and declared, "It's on tomorrow," tagging @CoachJim4UM, the official Twitter account for Harbaugh.

MLive is not identifying the individual as the Twitter author has not been independently verified.

A Michigan football team spokesman did not immediately return messages seeking comment.