ANN ARBOR, Mich. (AP)Michigan State players roughed up Michigan defensive back Ja’Den McBurrows in the Michigan Stadium tunnel following their game Saturday night.

After the fourth-ranked Wolverines beat the Spartans 29-7, social media posts showed at least three Michigan State players pushing, punching and kicking McBurrows in and near a hallway that does not lead to either locker room.

Michigan coach Jim Harbaugh said a second player, who he did not identify, was also attacked and one was injured and might have a broken nose.

”Two of our players were assaulted,” Harbaugh said. ”I saw on the one video. Ten on one. It was pretty bad.

”It needs to be investigated.”

University of Michigan Deputy Police Chief Melissa Overton said an investigation is underway in partnership with Michigan State University Police, and Michigan’s athletic department and football program.

”Situations like these, and the safety of the community, are taken very seriously,” Overton said.

Michigan athletic director Warde Manuel said Big Ten Commissioner Kevin Warren, who attended the game, is also looking into the fracas.

A message seeking comment was left with Warren and Michigan State athletic director Alan Haller.

”What happened after the game was completely unacceptable,” Manuel said. ”I talked to the commissioner. He’s looking into it. The police is looking into it because they’ve seen the video. This is not how we should interact after the game.

”This is not what the rivalry should be about. It should not be how it is remembered.”

Michigan State coach Mel Tucker said he did not know what happened in the tunnel after the game.

”I know it was a heated game,” Tucker said. ”We were trying to get our guys in the locker room. We’ll have to see what happened.”

It is the second straight game at Michigan that included an altercation in the long, narrow tunnel that goes from the locker rooms to the field.

Earlier this month, Penn State coach James Franklin said a policy change was needed to keep the process of teams using the tunnel more orderly.

A lot of heated words were exchanged and Michigan players said Penn State players threw peanut butter and jelly sandwiches at them as the teams headed to the locker room at halftime of a close game the Wolverines ultimately won in a 41-17 rout on Oct. 15.

Harbaugh said Franklin acted as a ”ringleader” and claimed the Nittany Lions stopped in the tunnel to prevent his team from accessing its locker room.

More AP college football: https://apnews.com/hub/college-football and https://twitter.com/AP-Top25. Sign up for the AP’s college football newsletter: https://bit.ly/3pqZVaF