A beach party organised by the Jyväskylä branch of the nationwide LGBTI rights organisation Seta was the target of a violent attack over the weekend.
According to a Facebook post (in Finnish) by the organisation, one person began kicking and punching participants at the event on Saturday night, and also bit two women, drawing blood.
Event organisers subdued the attacker, and police were quickly on the scene, the post added.
"The perpetrator said that he hates homosexual people, meaning this is clearly a hate crime against sexual minorities," Seta Jyväskylä wrote.
According to local newspaper Keskisuomalainen, the attacker was a young man who arrived around midnight and at first appeared friendly and eager to chat. There were about 50 people attending the event at the time.
The attack was the second incident involving threats or violence against sexual and gender minorities in Central Finland last week, after reports emerged on Tuesday that a youth worker was threatened by a passerby after helping young people paint rainbow colours on a stretch of pavement outside the town hall in the municipality of Hankasalmi.
Saturday marked the culmination of Finland's largest human rights event, Helsinki Pride, which celebrated its 30th anniversary with a streamed gala concert.
The Jyväskylä Seta chapter says it will hold its Pride Week as planned from August 16 to 22.