The Football Association has confirmed it will be investigating the crowd trouble at Luton and Sheffield Wednesday over the Bank Holiday weekend.
The investigations come after fans clashed on the pitch following the 2-2 draw at Hillsborough on Sunday which saw Sheffield Wednesday's relegation and Crystal Palace's survival in the Championship.
Then on Monday, seven people were arrested at Kenilworth Road after home fans invaded the pitch and threw missiles at visiting York players following the Minstermen's triumph in their Conference play-off semi-final.
In a statement released on Tuesday, the FA confirmed it will be investigating two separate incidents.
It said: "Following Sheffield Wednesday's fixture with Crystal Palace there were several reported incidents and the FA will this morning contact both clubs as well as local authorities to begin collecting information and evidence relating to the allegations.
"Similarly the FA will also be contacting Luton Town, following scenes during their fixture with York City yesterday.
"FA crowd control advisors were present at both fixtures and their reports into these matters have been received."
An FA spokesperson added: "The FA does not condone disorder either outside or inside football stadia and thankfully such problems remain infrequent in the modern game.
"However, any individuals identified as having taken part in any form of disorder should be dealt with appropriately by the authorities and issued with football banning orders as they simply have no place in our game."