At least 8 people were reported taken to hospitals following reports of an "active shooter" at Ohio State University that locked down the campus for two hours on Monday. One suspect was later reported killed, and the "shelter in place" subsequently lifted, media reported.
CNN reported that a "shelter in place" alert had been issued on Twitter shortly after 9 am the morning after many students had returned to the university after the long Thanksgiving Day weekend, and just two days after more than 110,000 packed the university's American football field for a match in which Ohio State defeated Michigan in a bitter annual rivalry on Saturday.
MSNBC reported that a "department chair" in the building that was the scene of the attack as saying that a colleague had been slashed in the leg with a machete. There were also unconfirmed reports that a car driven by the gunman had struck some pedestrians, the station said.
One student, Nicole Kreinbrink, sounded emotional as she said she was getting ready to cross a street on campus and saw a car coming that "just swerved and just ran into a whole group of people and hit a cop really bad. I ran over there and saw the cop, he's rolling around and I could tell he's in a lot of pain".
She said she wanted to try to help the policeman but that "all these people were running and screaming and yelling, the girls told me get out, get out so I just ran with them".
Live television reports from the campus showed a massive police presence in a part of the campus, including armed police, ambulances and fire engines.
Students on the massive Ohio State University were told to "Run Hide Fight", as an "active shooter" alert was issued by the university's emergency management on Twitter.
The alert was issued for Watts Hall at 19th and College Street, home of the Department of Materials and Science engineering on the huge campus which has some 66,000 students - third largest in the US - in the Ohio state capital of Columbus, about 230 kilometres south of here. It covers almost 6,500 hectares and has 1,293 buildings.
Ohio Gov. John Kasich, a former candidate for the Republican presidential nomination, tweeted that the statest "thoughts and prayers go out to Ohio Sate Community".