Tonga's Rugby Union says people whose violent actions bring the game into disrepute will be banned from playing or watching matches.
This comes after a secondary school rugby match between Liahona High School and Apifo'ou College was cut short last week when brawling ex-students marched onto the field.
The Union's Chairman, Epi Taione, says the actions of a few have negatively impacted on the sport's reputation.
"They use rugby, after the rugby game is the time where this fighting goes on. So it is really for us, in terms of rugby, to make sure that it doesn't really associate with our sport. Anyone who brings the game into disrepute, we have every right to remove them from the grounds or ban them for life from playing the sport."
Epi Taione says the union will work closer with school principals to target the trouble makers.