Collingwood and Carlton fans involved brawl at MCG

A man has been injured after fights broke out during Collingwood's 19-point win over AFL rival Carlton at the Melbourne Cricket Ground.

Separate fights broke out at the end of Saturday's game, with one spectator describing it as "Collingwood (and) Carlton supports just full-on punching each other".

One man was treated for minor injuries, and police and security stepped in to prevent further fights, Victoria Police said in a statement.

The injured man did not want to make a statement but officers spoke to the alleged offender and released him pending further inquiries.

"I saw a bunch of dudes punching on," one witness told Nine News Melbourne.

"I saw a bunch of kicks but they missed."

A woman at the game named Robin told radio station 3AW the fights broke out in an area full of Carlton supporters.

"There were four fights, four full-on punch-on fights where people were knocked out," she said.

"And security just didn't react quick enough, so the members of the public had to get in, including me, to stop these fights.

"I missed the last five minutes of the game because I was breaking up fights.

"What I was disappointed in was the security people and their inability to act correctly, the lack of police, it was just terrible."

But a spokesman for the MCG said: "We are comfortable with our security's response along with that of police."

"Our security and police deal with these incidents as they occurred," he said.

"If police charge someone, we will fully cooperate."