West Ham United defender George McCartney and his international team-mate Keith Gillespie have been fined by the Irish Football Association following an incident on last week's return flight from Iceland.
The Northern Ireland duo have been told that "such behaviour will not be tolerated in the future" after fighting between themselves as the Icelandair flight was about to depart Reyjkavik for Heathrow.
Gillespie, who scored a last-gasp own goal in Northern Ireland's 2-1 defeat to Iceland, later apologised for the incident.
In a statement, the IFA said: "Issues surrounding the incidents which occurred involving certain players within the Northern Ireland squad during the trip to Iceland have now been addressed and resolved.
"The IFA wishes to apologise to any members of the public who were affected in any way by the behaviour of these players."
IFA president Raymond Kennedy added: "The IFA has been shown up in a poor light as a result of behaviour, which of course is unacceptable.
"While the public apology from Keith Gillespie goes some way towards a recognition of that, the players concerned have been told quite categorically that such behaviour has caused unnecessary embarrassment to the IFA in the eyes of the football world and the public as a whole and will not be tolerated in future."