BBC quotes

I’ve long given up trying to figure out the BBC’s policy on the use of quotation marks. I’m beginning to suspect there isn't one.

Take a look at two of today’s headlines from BBC News.

Germany arrests al-Qaeda suspect
German police have arrested an Algerian man wanted in Italy on suspicion of recruiting suicide bombers for attacks in Iraq.

Police question 'al-Qaeda' suspect
A 24-year-old British man was arrested on Thursday under the Terrorism Act and taken to Paddington Green police station in London.

What’s the difference?

Update
The headline on the German arrest has been rewritten. It now reads Police pounce on 'al-Qaeda cell'. But why the quotation marks? It's not a reference to a quote in the article. Stranger and stranger.

Update
Once you get started on this kind of thing, it's difficult to stop. Here's another BBC headline with inexplicable quotation marks: European defence 'deal' reached. Once again, it's not a reference to a quote in the article. So why the quote marks?