Google uses heuristics to find "links". These may not come from broken links at all. Google scans your sites source code for anything that "looks" like a URL.
var s = "2370/2317"
Or a data attribute like:
Because of the slash, Googlebot would think it looks like a relative URL. It will then try to follow it and get the 404 errors.
Despite the fact that it was a heuristic (not a actual broken link) that caused Googlebot to find the 404, Google will report these 404 errors in Google Webmaster Tools.
The good news is that this doesn't hurt your site at all. The only down side is that it clutters up this report and makes it hard for you to find any real 404 issues.
var s = "2370" + "/" + "2317";
Here is what Google's John Mueller (who works on Webmaster Tools and Sitemaps) has to say about 404 errors that appear in Webmaster tools:
HELP! MY SITE HAS 939 CRAWL ERRORS!!1
I see this kind of question several times a week; you’re not alone - many websites have crawl errors.
- 404 errors on invalid URLs do not harm your site’s indexing or ranking in any way. It doesn’t matter if there are 100 or 10 million, they won’t harm your site’s ranking. http://googlewebmastercentral.blogspot.ch/2011/05/do-404s-hurt-my-site.html
- In some cases, crawl errors may come from a legitimate structural issue within your website or CMS. How you tell? Double-check the origin of the crawl error. If there's a broken link on your site, in your page's static HTML, then that's always worth fixing. (thanks +Martino Mosna)
- You don’t need to fix crawl errors in Webmaster Tools. The “mark as fixed” feature is only to help you, if you want to keep track of your progress there; it does not change anything in our web-search pipeline, so feel free to ignore it if you don’t need it.
- We list crawl errors in Webmaster Tools by priority, which is based on several factors. If the first page of crawl errors is clearly irrelevant, you probably won’t find important crawl errors on further pages.
- There’s no need to “fix” crawl errors on your website. Finding 404’s is normal and expected of a healthy, well-configured website. If you have an equivalent new URL, then redirecting to it is a good practice. Otherwise, you should not create fake content, you should not redirect to your homepage, you shouldn’t robots.txt disallow those URLs -- all of these things make it harder for us to recognize your site’s structure and process it properly. We call these “soft 404” errors.
- Obviously - if these crawl errors are showing up for URLs that you care about, perhaps URLs in your Sitemap file, then that’s something you should take action on immediately. If Googlebot can’t crawl your important URLs, then they may get dropped from our search results, and users might not be able to access them either.
It is also possible that Google is adding these numbers to the URL one at a time. Your site behaves in an odd way. I found your site and tried
/90s-unforgetable-memories-just-have-a-look/2317/ which returns the same pages as
/90s-unforgetable-memories-just-have-a-look/. Only when I put a second number on the URL, then it returns a 404. It might help to configure your site to eliminate this duplicate content problem. One way would be to use this redirect directive in your .htaccess file:
RedirectMatch permanent /([a-z0-9\-]+\/)[0-9\/]+ /$1
That rule will effectively remove all the trailing numbers and slashes from your URLs and redirect back to the article. You'll have no more duplicate content or 404s then.