  (Abridged) Spiral galaxies often have extended outflows that permeate beyond
the region of the disk. Such outflows have been seen both in starburst
galaxies, actively star forming galaxies and galaxies with an AGN. In the
latter galaxies it is unknown whether the large-scale outflows are driven by
star formation activity or purely by the active nucleus. The aim of our
investigation is to study the frequency of extended minor-axis outflows in
edge-on Seyfert galaxies to investigate the role of the AGN, the circumnuclear
environment and star formation activity within the disk regions, and their
importance for IGM enrichment on large scales. Narrowband imaging in two
different ionizational stages (H-alpha and [OIII]) was performed to attempt a
discrimination between processes associated with the active nucleus and those
connected to star forming activity within the disk. The H-alpha morphology of
the Seyfert galaxies is usually complex, but only in three out of 14 galaxies
did we find evidence for minor axis disk outflows. At the sensitivity of our
observations [OIII] emission is generally detected only in the nuclear region.
Overall, our results show that extraplanar emission of similar brightness and
extent as in the previously known cases of NGC3079 and NGC4388 is not common in
Seyfert galaxies of otherwise similar properties. Comparison with our previous
results shows that for nearby edge-on spiral galaxies star formation may be a
more powerful mechanism for producing DIG than AGN activity. While in general
AGN activity undoubtedly plays some role in driving minor-axis outflows, this
probably requires higher AGN luminosities than are encountered in our small
distance-limited sample.
