BERLIN (AP) — Police say a heated clash between left-wing and right-wing groups at the Frankfurt Book Fair has resulted in three arrests.

Frankfurt police said the confrontation happened late Saturday at an event organized by German 'new right' publishing company Antaois involved about 400 people.

Police said Sunday that three people were temporarily detained, but didn't specify to which group they belonged. They urged witnesses to come forward.

A spokeswoman for annual book fair denied reports of a brawl, but said there had been "unpleasant comments" from right-wing activists.

Book Fair spokeswoman Katja Boehne says organizers haven't decided what steps to take to prevent such incidents in future.

Antaois is considered part of the intellectual vanguard of nationalist movements in German-speaking countries.