Creating a Qt install package with InnoSetup : missing images

Question

I'm developing a Qt app in Qt Creator. I'm creating an install package via InnoSetup. And everything works OK except all the images are missing in the installed program (running it in Qt Creator works fine).

I'm using The Qt Resource System

In my .pro file I have

RESOURCES += \
res/resources.qrc

If in my resources.qrc I have something like this:

<RCC>
   <qresource prefix="/icons">
       <file>4000003.png</file>
       ...
   </qresource>
</RCC>

I access my images for example like this:

title->setIcon(QPixmap(":/icons/" + QString::number(id) + ".png"));

The structure of my directory is :

MyApp
 -sources files (i.e. `.cpp`, `.h`) 
 -res/
   -all the images
   -resources.qrc
build-release
 -release/
   - MyApp.exe

So should I have exactly the same struture in InnoSetup? Meaning I should have the build-release\release directory and the MyApp\res as well? Because I tried that and it didn't help.