Professor Ethan Schmidt has been shot dead on the campus of Delta State University in Cleveland, Mississippi.

Ethan Schmidt worked in the history department.

Multiple law enforcement agencies are searching for the gunman who is still at large but reportedly now off campus.

All campus buildings were locked from the inside and officials had advised people to shelter in place.

Ethan Schmidt, who specialized in Native American and colonial history, was shot in his office inside the university’s Jobe Hall building, police said.

Don Allan Mitchell, a colleague, called Ethan Schmidt “a gentleman in every sense of the word” and “a terrific family man”.

Roughly 3,500 students are enrolled at the university near the Arkansas border.

Freshman Noah Joyner, 18, said he stayed inside a bathroom in his dorm buildings during the lockdown.

“There were like people banging on the doors to have somebody let them in,” Noah Joyner, a swimmer at Delta State, told the Associated Press.

“It was pretty terrifying to hear people banging on the door.”

Police helicopters are circling campus and officers have swept buildings, which have now mostly been evacuated.