PHP scripts are not being executed

My PHP version: PHP 5.3.3 (cli) (built: Aug 6 2014 05:54:27) ON CentOS release 6.5 (Final)

I recently installed virtualmin (moving from zpanel) on my VPS.

What strange thing I found today is that after installing PHPMyAdmin in virtualmin I navigated to phpmyadmin URL and instead of seeing the PHPMyadmin page I am seeing raw php code.

I then created another subfolder within one of my domain and pasted my websites files here and again as I navigated to the address it shows me raw PHP code of the index.php file.

No idea what is going on here. I also searched on internet and been trying to apply solutions posted for past couple of hours but no joy so far.

When I make a folder with FTP access (Filezilla) and create a sample php file with following content, it does get executed.

<?php phpinfo(); ?>

However, as I said above phpmyadmin’s php code and my site’s code is not being executed.

Any idea what can be the problem?, any help will be appreciated.