Unidentified Flying Objects

On the 24th May 2009 I climbed Helsby Hill in Cheshire to take some panoramic photos of the  Stanlow Chemical Plants below. An aeroplane flew over head and I couldn't resist taking a shot. The sky was cloudless and a brilliant blue.

When I examine the photo later that day I noticed two objects that definitely were not there when I took the shot.    Click on image to enlarge.

WHAT ARE THEY?