I have found these posts in Arabia in September/October. I have spoken with many people about the finding to have more info about them but nobody seems to have noticed them. When i manage to define the adress or more accurate location, then i can search from archive by this keyword. It must be part of some previous building that has laid there. At the surrounding area i haven't noticed any other old building. But there is a church. http://fi.wikipedia.org/wiki/Paavalinkirkko_(Helsinki)
Also i have found similar posts from the boarder of Helsinki and Vantaa.