A 29-year-old Minneapolis man faces felony charges after allegedly threatening in online posts and text messages to kill his former colleagues.

Frankie Davis was booked into Hennepin County jail late Tuesday on a charge of making terroristic threats and was being held in lieu of $80,000 bail. He is slated to appear in court Thursday afternoon.

Davis is accused of sending multiple threatening messages via text and social media, including one post on Facebook that said, “It’s not Terrorist It’s Workplace violence,” according to a criminal complaint filed Wednesday.

Another post read: “If revenge is sweet and a dish best served cold well, get ready … the ice cream man is coming.”

Davis was apparently upset after he was let go from his job in the U.S. Bank building in downtown Minneapolis, authorities said. In one text message to a co-worker, he discussed beheading his boss and throwing the body off the 19th floor, adding, “Where’s ISIL when you need them,” the complaint said.

He also allegedly made posts “glorifying” several recent mass shooting suspects, including Jared Lee Loughner, who in 2011 fatally shot six people in Arizona and wounded 13 others, including former U.S. Rep. Gabrielle Giffords, and Gavin Long, who’s suspected of killing three police officers in Baton Rouge, La.

“Based on this text and other behavior, people at the workplace were terrified,” the complaint said, and U.S. Bank hired an off-duty Minneapolis police officer to provide extra security.