Update: Google Search seems to be back to normal, the issue was caused by "human error" according to Google.
Google Search is currently not functioning correctly and returning "this site may harm your computer" on every search link.
If you search for BBC News you will get the following:
And if you attempt to visit any search results you will be met with
"Warning - visiting this web site may harm your computer!
* Return to the previous page and pick another result.
* Try another search to find what you're looking for.
Or you can continue to http://news.bbc.co.uk/ at your own risk. For detailed information about the problems we found, visit Google's Safe Browsing diagnostic page for this site.
For more information about how to protect yourself from harmful software online, you can visit StopBadware.org.
If you are the owner of this web site, you can request a review of your site using Google's Webmaster Tools. More information about the review process is available in Google's Webmaster Help Center."
At the time of writing Google representatives were unavailable for comment.