KENT, Ohio -- Gun-rights activists led by Kent State University graduate Kaitlin Bennett marched on the KSU campus Saturday afternoon, openly carrying a variety of weapons and creating a tense stand-off with angry counter-protestors.

Hundreds of police officers from all over the state were deployed to keep the peace, lining up in riot gear to physically keep the two groups apart.

No serious injuries were reported, according to the university, although one man seemed to be knocked unconscious and a protestor had an abrasion on his forehead.

There were four arrests. All were charged with disorderly conduct, with one additionally charged with assault on a police officer.

The gun-activist group numbered about 50 people, some with weapons slung across their backs or in holsters. They began their march around 2:30 p.m. and were soon confronted by about 100 protestors as they walked passed Kent State's student center.

Officers struggled to keep the two sides apart as protestors pressed against the police line, hurling insults at the marchers. What ensued was a standoff, punctuated by spotty discussions between groups, screaming matches and insults.

Police pushed back protestors, who pushed back on them.

Gradually, the protestors pushed the gun-rights group back to the front of the student center. After about an hour, the guns-rights protestors returned to the public parking lot across the street, where the march began, flanked by police and followed by protestors.

As of about 5 p.m., guns rights protestors were still in the parking lot. Counter-protestors left at about 4 p.m. State troopers began to leave around 4:30 p.m., though it seemed local police were still grouped in the area.

Marchers were campaigning for conceal carry on Kent State's campus. Kent State currently does not allow students and faculty to carry weapons. It does allow visitors to open carry. Bennett originally planned to hold a rally with a lineup of speakers.

After a long chain of back-and-forth between organizers and the university, including a letter where officials required student sponsor Liberty Hangout to pay security fees and to ban guns at the event, Bennett changed the rally to a walk.

At a university press conference this evening, president Beverly Warren said the university put out a call for mutual aid. There were hundreds of police from throughout Ohio, including police from Ohio University and the University of Cincinnati.

She called their performance exemplary.

"We anticipated this day might present some challenges ... as a public university with this beautiful campus, we are open to all who (want to come here to express their views but we will always do everything necessary to safeguard our university and the people who visit us."

The main image on this post was updated for clarity. Read more about the rally here.