The protest came four days after George Floyd died while in police custody in Minneapolis.
"In a span of just 24 hours, I walked across a Harvard virtual graduation stage into the back of police van alongside other peaceful protestors -- both of which I am equally proud of," Towns said Saturday afternoon as part of a series of tweets.
In a span of just 24 hours, I walked across a Harvard virtual graduation stage into the back of police van alongside other peaceful protestors-both of which I am equally proud of. pic.twitter.com/qtvXmw0Fwq— Seth 💤 (@seth_towns17) May 30, 2020
In a video posted by Eleven Warriors, Towns is seen repeating, "Say his name!" while officers put his hands behind his back.
Protesters responded by saying, "George Floyd!" Someone in the crowd shouted, "He wasn't touching anybody," as officers detained Towns. Another person yelled, "That is a Harvard graduate right there!"
Footage of Seth Towns in police custody earlier Friday at the scene of a protest in Columbus. Towns, an incoming Ohio State basketball transfer, graduated from Harvard Thursday.— Eleven Warriors (@11W) May 30, 2020
Towns is no longer in police custody and is safe at home, according to a source. pic.twitter.com/kFptHH63BN
Towns was detained briefly and was not arrested, Ohio State spokesman Dan Wallenberg said.
Towns told SportsCenter in an interview Saturday night that he joined the protest to make sure his voice was heard.
"I won't stop. I will continue to use my voice to speak out for the people who are unheard, and that's what I did. Voice is so important," Towns said. "And when I say 'voice,' I'm not talking about speaking, per se; I'm talking about actions. I'm talking about going out and protesting, and doing your duty as a member of this democracy."
There have been protests around the country since Floyd's death. Floyd, who was black, died after Derek Chauvin, a white police officer, kneeled on his neck for several minutes. Chauvin was charged with third-degree murder and second-degree manslaughter on Friday.
Chauvin and three other officers who were involved in the incident, including two who helped to hold Floyd down, were fired earlier this week.
On Thursday, Ohio State men's basketball coach Chris Holtmann tweeted that he was "shocked and saddened by the senseless violence to unarmed and defenseless black men."
Holtmann told ESPN he spoke with Towns after the incident on Friday night.
"I did talk to Seth last night," Holtmann said. "He's back at his apartment. We had a great conversation."
Holtmann on Saturday issued a statement saying "we fully support our players' right to peacefully protest" and that "we pray for safety in our city, state, and around the country."
On Saturday afternoon, Ohio State athletic director Gene Smith tweeted, "Proud of you, Seth!"
Towns graduated from Harvard with a bachelor's degree in sociology on Thursday. The 6-foot-7 forward averaged 16.0 points and 5.7 rebounds last season before announcing his transfer to Ohio State, where he'll be immediately eligible next season.
A statement from Coach Amaker. pic.twitter.com/vCG0YO9YBP— Harvard Basketball (@HarvardMBB) May 30, 2020
Harvard coach Tommy Amaker tweeted Saturday that he fully supports Towns' "continued fight for social justice" and that he was proud of his former player.