Around 7000 people registered for the event on Facebook, the organisers said.
The gathering at the Citizen Square in Helsinki was intended to show solidarity with refugees.
Similar events were held all over Europe on Saturday. In Finland, the picnics were held in Helsinki, Espoo, Vaasa, Jyväskylä and Tampere. In Tampere’s Sorsa park, less than a hundred people attended the event, according to police estimates, and in Jyväskylä’s Church park, there were 30-40 people in attendance.
There were no reports of public disturbance associated with the events. The Helsinki police said they would make provisions prior to the events, just like with any other event with a similar size.