Can I use a `div` element inside an `a` tag?

In FF, Opera and Safari print in screen very well, but when I use the inspect (or firebug), it doesn't find the element insight of the a tag.

For example, a typical HTML:

```
<a href="#">
<div>lorem ispum</div>
<div>lorem ispum</div>
</a>

```

Is it an error?