Adding target
option do the trick.
|facebook| |tw|
.. |facebook| image:: http://www.summerbounce.ca/wp-content/uploads/2012/11/facebook-logo-small.png
:target: http://www.facebook.com
.. |tw| image:: http://www.summerbounce.ca/wp-content/uploads/2012/11/facebook-logo-small.png
:target: http://www.twitter.com
Anyother better solution, always welcome.