Redirect 404 errors to a separate log file

[kustodian]

I have been trying for a whole day to figure out how to redirect 404 errors
to a separate log file. I managed to do this in the server directive:

error_page  404 = @404;
location @404 {
        error_log  /var/log/nginx/404.log;
}

This does write all 404 errors to 404.log, but the problem is that it also
writes these errors in the default error.log, and I don't want that. I want
404 errors to be writtent to only into the 404.log.

Do you have an idea how to do this?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,230087,230087#msg-230087