Two young men were in the canoe when it overturned. One of them managed to get to land.
The search uses drones flown over the lake and dog patrols along the shores. During the morning, the sea rescue service also joined in.
The alarm to the police came via SOS at 7 pm on Wednesday.
They searched late into the evening, then decided to call it off, and resumed the search today, says police spokesperson Katarina Rusin.
