3 minor explosions at 3 tube stations, and a bus has had its windows blown out in Hackney. The stations involved are Oval, Shepherd's Bush and Warren Street where I was this morning!

All the explosions involved only detonators, and they went off around 13:11.

Only one injury is reported so far.

UPDATES: Latest from the BBC...

The attempted bombings in London were designed to kill people, the head of the Metropolitan Police has said.

But Sir Ian Blair said evidence left at the scenes could be very helpful to police and added "the intention of the terrorists has failed".

It is believed devices only partially exploded at four locations, three at Tube stations and one on a bus.

BBC security correspondent Mark Urban said initial indications were that the devices were put together in a way very similar to those used two weeks ago.

He said there were suggestions that the rucksacks themselves, as well as the choice of three tube trains and one bus as targets, all suggested a similar method of attacks.

There was also speculation that the devices were so similar to those used two weeks ago that they may even have been part of the same batch.