I get a text file:

<p>...</p>
<pre>
...

...
...
...
</pre>
<p>...</p>
<p>...</p>
<p>...</p>
<pre>

...
...

...
</pre>
<p>...</p>

Notice that: there are some empty lines between [pre]...[/pre].
I want to delete them.
But, I want keep those in [ p]...[/p]
The text file becomes:

<p>...</p>
<pre>
...
...
...
...
</pre>
<p>...</p>
<p>...</p>
<p>...</p>
<pre>    
...
...    
...
</pre>
<p>...</p>

I use the cmd below to located them:

/<pre>\n\zs\_.\{-}\ze\n<\/pre>

But I don't know what to do next!
I need a one-line-cmd to do this.
Any idea? Thanks!
The simpler, the better!

---

Edit: Thank you all. I just figure out how to do it with the help of my another question

:g/<pre>/,/<\/pre>/s/^$\n//