In an online alert, the school, located in Columbia, South Carolina, told people to stay indoors and seek safe shelter. No other details were immediately available.
"We are continuing to monitor the situation," the university said on Twitter. "No new information available. Continue to stay indoors."
The State newspaper in Columbia reported that all buildings at the university had been locked down and that Governor Nikki Haley cut a news conference short on Thursday due to security concerns.