Tapered blue stoneware vase/bottle - possibly Scandinavian - POL mark?

Hi

This is a vase/bottle which narrows towards the top, slightly indented in places and with a coiled look.  The glaze is various shades of blue.  The mark to the base could be 'POL' in a square but could also be 'N' and an 'O' with a line through.  Thought it could possibly be Scandinavian?

Would appreciate any comments.

Thank you