There was no information immediately available on the extent of injuries suffered, but according to eyewitnesses, the person wounded was part of the event's security personnel and walked to an ambulance called to the scene.
A group of young men describing themselves as "patriots" started a fight after being refused entrance to a discussion event dealing with the Finnish extreme right. Bottles were also used as weapons in the fray.
Eyewitnesses say that the perpetrators fled the scene. Police are investigating the incident as aggravated assault.
The event in the city library was organised in connection with a presentation of the book Äärioikeisto Suomessa, (or "The Finnish Far-Right") by Mikael Brunila and Dan Koivulaakso.