In order to block an entire country or region of the world from accessing your site you can go to http://www.countryipblocks.net/ and select the country or countries you would like to block, select .htaccess deny, and hit generate.
This will generate the necessary code to paste into your .htaccess file to block countries based upon IP ranges.
Note that you should save these changes LOCALLY on your machine as well. In the instance your .htaccess file needs to be regenerated you will have to update this information again.
