RewriteEngine On 

RewriteCond %{REQUEST_FILENAME} -f [OR] 
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^(.+) - [PT,L] 

RewriteRule ^(.*) index.php?uri=$1

#example assuming /images/banner.jpg exists that will be showed but
#but if /news/customfolder/article1.php does not exist that will be sent to index.php as the $_GET['uri'] value