You don't need to add an <a> element as anchor, you can simply add an ""id" attribute:
Code:
<div class="image" id="someid"><img alt="" src="..." /></div>
and then use <a href="..."> as normal.
PS. Do not add some meaningless text in the "alt" attribute. The alt attribute is intended to be shown/read when the image is not displayed. It should be something descriptive if the image is something important, but if it's just a decorative image it's better left blank.