This error is generated by the Google News' extracting algorithms to avoid including in Google News incorrect pieces of text, such as user comments.

In order to avoid this error, you want to write your articles in a way to not look like, for example user-comment. The article should contain paragraphs, but each one should have well-formatted and long-enough sentences. Two-three word sentences are typical for a commenter who's in rush, not a journalist. However, don't think in numbers. We can't say a 3 paragraph article and each paragraph having 3 sentences will be successfully indexed by Google News. You want to write proper articles, not one-liners.

According to Inbal (Google Employee) the "article fragmented" error can be caused by:

1. a very short article,

2. it's broken in two by the <p> tags in the article body,

3. the article body consists of a small fraction of the text on the page.

Very good example for a website which has very well formatted articles is Wikipedia, where most of the entries have proper paragraphs with well-formatted sentences.