Blocking entire countries

Before I used Mollom I realized that in my logs the spammers have created a comment 294 in one of my nodes.
Of course the comment is hidden since It will take years to get to that comment.
I decided to removed the node and create a new one altogether with installing Mollom

I can see in my stats still the page not found visits from countries like Russia or China looking for that page or the comment.
I want to get rid of those visits and I thought that perhaps I can block countries like those not related to my page.

Your help on how to do it will be welcomed.
Perhaps it is harmless and you think that I can let it go, but it bothers me to see them trying to reach my page.
I blocked some IPs, but I would like to block certain countries better.