London Punked?

Coming out of London this morning are reports of "incidents" on the underground. These "incidents" mirror the bombings of two weeks ago. I think this is a prank. One eyewitness reported that after the "bomb" went off the "bomber" said, "Oh fuck."

UPDATE 10:00AM: The current story floating on this is that this was a terrorist attack and that the plastic was a bad mix. Only the detonators went off. Armed police, rare in London, have entered University Hospital, possibly to secure an injured bomber. I don't have a clue if this is true or not, just passing on what I hear on British radio.