By Brendan O'Brien
(Reuters) - Ball State University of Muncie, Indiana, on Friday warned that an individual reported seeing a gunman on campus and urged students and faculty to seek shelter.
The college, however, said media reports of a hostage situation were inaccurate.
The university said on its website that "an individual in the recreation and wellness building shouted that there was a gun." University police were assessing the situation, the college website said.
"The search of the affected facilities continues. Remain in a safe location," the university has posted several times on Twitter.
Graduate student Jessica Souto told Indianapolis television station WTHR in a phone interview that she was running on the third floor, indoor track at the Human Performance Lab on campus when she saw people looking out the windows.
She said she was told to go downstairs because the building was on lockdown.
Souto said she made it to the first floor where she saw police officers putting on bullet-proof vests and ushering people away.
"It was definitely disconcerting a little bit, to not really know what's going on and having people checking Twitter and seeing what's going on there and having friends and family call, so it was a little scary," Souto told the station.
WTHR showed aerial video of over a dozen police cars with lights flashing stopped at an intersection on campus.
The station also showed amateur video of police officers apparently armed with rifles walking through a concourse at a building on campus, as they searched for a gunman.
An explosion heard on campus was determined to be an accidentally discharged service weapon outside the secured perimeter of the scene, the school said on its website.
About 21,000 students are enrolled at Ball State, located in Muncie, 60 miles northeast of Indianapolis.
(Reporting by Brendan O'Brien in Milwaukee, Wisconsin; Additional reporting by Alex Dobuzinskis in Los Angeles; Writing by Scott Malone; Editing by Barbara Goldberg, David Gregorio and Lisa Shumaker)