A student at City College was arrested for allegedly sending messages threatening to "shoot up" the Manhattan school last week, and then released without bail, The Post has learned. City University of New York officials issued a warning to the school community on Monday about the case involving 21-year-old Din Bajrektarevic, who has been suspended and barred from campus. Bajrektarevic, of Old Bridge, New Jersey, was busted when he returned to the college in Harlem on Nov. 25 following Thanksgiving — two days after he had allegedly sent the hateful messages. "When I shoot up the school, know who is to blame," one of the missives said, according to the criminal complaint against him. "The city will go to war you dumb N***** M****** (comparing the defendant's race to an animal)," the court document states. “Your brains will be left on the f****** pavement.” The NYPD charged him with making terroristic threats, cops said. The Manhattan District Attorney's Office prosecuted him on charges of second-degree aggravated harassment as a hate crime, first-degree harassment as a hate crime and second-degree aggravated harassment. None of the charges, including the one filed by cops, were eligible for bail under New York state law, so he was released on his own recognizance. A restraining order was also issued against him, the DA's office said. In its message to the school community, City College said that its public safety office "acted on the threat with the NYPD and the FBI, and the student was promptly identified and arrested." "All CCNY Public Safety Officers have been informed that Mr. Bajrektarevic has been suspended and barred from campus, and they are fully prepared to enforce the bar should he attempt to enter the City College campus,” the email obtained by The Post states. Safety officials also released a photo of the student — asking for the community to "remain alert, and should you encounter Mr. Bajrektarevic on the City College campus, please immediately notify CCNY Public Safety.” The email noted: "We have no reason to believe at this time that Mr. Bajrektarevic intends to violate the directive and attempt to enter the City College campus. Nor do we have any indication that Mr. Bajrektarevic is in possession of any firearm or any other deadly weapon.” Bajrektarevic's next court date is set for Jan. 11. He couldn't be reached Tuesday. His defense attorney did not immediately return a request for comment.