It seems there are some letters on this bowl with the design of a viking ship which has been found in Nishpaur in the northeast of Iran (probably from the early 10th century AD): http://www.ichodoc.ir/p-a/CHANGED/43/IMAGES/43_10_1b.jpg are they Runic letters?
No, so far as I can see none of the symbols on the bowl look like runes. Also, calligraphic runic inscriptions are almost nonexistent. On the hypothesis that there is indeed a connection to runes, a possible explanation is perhaps that these are ornamental symbols imitating runes, mirroring the use in Europe of imitations of the Kufic script for decorative purposes around the same time.
There is a Kufic word (in white color) on the sail which seems to be الملک (al-malik) which means "king" but other ones in black color, as you said, are probably just ornamental symbols.
