I just heard from a friend who was on the tube this morning and I think I have explanation for the early stories that it was a "massive power failure"
That's what they were telling the passengers while they were trying to evacuate them from underground rather than saying "there's been a bomb at Edgeware and there might be one on this train too" which could perhaps cause people to panic.
If I had my druthers and was a passenger, I'd want to hear it was a power failure and the real story later.
The idiots in Iraq have killed the Egptian Envoy.