Oxford United fans broke ten seats at the Sixfields stadium during their recent match against Northampton Town.
A spokesperson for Northamptonshire Police said: “The seats were in the South Stand, where away fans were sitting during the game on Saturday, September 12.
“At the end of the match, part of one of the broken seats was thrown towards the pitch,” he added.
Witnesses, or anyone who knows anything about this incident, can call Northamptonshire Police on 101.
Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111 or use the anonymous online form at www.crimestoppers-uk.org.