php - Redirect Non-WWW to WWW URLs

When people access my domain it is redirected to
http://www.mydomain.com/en/index.php using php code.I added the following code in .htaccess

RewriteEngine on
Options +FollowSymlinks

RewriteBase /
RewriteCond %{HTTP_HOST} !^www\.
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]
RedirectPermanent /pages/abc-123.html http://www.mydomain.com/en/page-a1/abc.php

to redirect people from non www to www,

Still users can access by typing both http://mydomain.com/en/page-a1/abc.php and http://www.mydomain.com/en/page-a1/abc.php URLs

Does anyone know the method to completely redirect to http://www.mydomain.com/en/page-a1/abc.php even if user typed http://www.mydomain.com/en/page-a1/abc.php, and prohibit accessing URLs without www.