The university shut all of its sites in Chicago and Orland Park while investigators continue to look for the person responsible for the threatening graffiti.
Officials hope the Catholic liberal arts college will open as soon as possible.
Meanwhile, officials at the two high schools and two elementary schools say they expect to resume classes on Tuesday.
While it's unknown whether the messages at either school are credible, students arriving at a closed Malcolm X Monday afternoon reacted to the threats. "I think it's like a game for some people. They have to realize some people are out here actually trying to go to school. You're hurting those people when you do stuff like that," said Eriberto Vazquez, Malcolm X College student. "It's alarming. You don't know what's going on, if it was false or if it was a prank or if it's true," said Yolanda Stewart, Malcolm X College student. SXU has set many students up in hotels or paid the airfare of others so that they can go back home until the decision is made to reopen. Both St. Xavier and Malcolm X have set up hotlines for students to get additional information. Malcolm X was asking those who have classes late Monday afternoon to call before they come over. There were already plenty of students congregating outside of the building around 4 p.m., waiting for it to reopen.. A group of ministers made a call for more gun control laws after the threat of violence at SXU. Twenty-five ministers gathered at Saint Xavier University, 3700 W. 103rd St., Monday. The ministers were calling for tougher penalties for people who are caught selling guns illegally. The group wants the state's general assembly to take steps to stop what they call a pandemic of violence in the Chicago area. At NIU's Naperville campus, under a cloud of gun violence, gun-control proponents gathered to talk about ways to stop all the violence. One of the speakers, Garrett Evans, survived the shooting almost one year ago at Virginia Tech. "Door opens really, really fast, the first thing I see is a .22 automatic unloading before I ever saw the guy's face, 'pop, pop, pop, pop, pop,'" said Evans. Most of the audience while sympathetic to the victims, oppose new gun control laws. The National Rifle Association urged members to turn out, and they have in large numbers. "Legislation that is proposed in Springfield only infringes on the rights of law-abiding people. And we are not for those, we are going to oppose those," said Richard Pearson, Illinois NRA Executive Director. "Instead of going after people who want to protect themselves and taking our rights away, you go after the people that are making the rap music and video games that are where these teenagers practice how to shoot each other," said Ronnie Rohrbak, NRA member. Chicago area campuses weren't the only ones impacted by threats Monday. Administrators at Oakland University near Detroit say they found threatening messages on campus Saturday. The university was closed Monday. The Detroit Free Press reports the graffiti referred to possible campus attacks Monday. The dorms were still open but students were encouraged to go home if possible. Classes were scheduled to resume Tuesday.