htaccess - throw 404 if url/q string doesn't contain specific word

how to throw 404 if query string doesn't contain the word "news"
all query string must contain "news"

example:

mysite.com/index.php?q=obama-gossip-news ->Okay
mysite.com/index.php?q=obama-gossip-etc ->redirect to 404.php

thanks

 

Since it's a query string you should do something like:

RewriteCond %{QUERY_STRING} !news [NC]
RewriteRule ^(.*)$ /404.php [L]

Code (markup):

If the word "news" is missing from the string it should redirect it to your error page.