Disable direct access to certain files (include)

Disable direct access to certain files (include)

I'm triyng to blobk access to certain files. I have on my server many
files like this
filename_sql.php
Basically i need to disallow user to access directly to sql.php files:
http://url.com/filename_sql.php <<<
I have created an htaccess with this code, but i can access files direcly
calling url. What do I wrong?
<Files ~ "\.sql(.php)?$">
Order allow,deny
Deny from all
</Files>
Thanks all.