How do you pronounce Iskra?

Excuse me, but could you please clarify for me the correct pronunciation of the name "Iskra"? I've seen it written down several times, but I'm not entirely sure how it's meant to be said. Is it pronounced with a long "I" sound, like "eye-skra," or perhaps with a shorter, sharper "I," like "iss-kra"? I'd really appreciate your help in getting this right.