Bird of Prey ID?

I saw this largish BOP on Sunday at Lodmoor.  It was quite high up hovering above the reedbeds. I couldn't see any detail because I was almost looking straight up into the sun but I wondered if any of you clever people out there are able to ID from a silhouette?  Sorry for the poor photos.

Answer: Kestrel

There is something new to learn everyday...

http://www.flickr.com/photos/skylark58/