This series of 'as news breaking' emails from another newsgroup might
clarify to date:

Hi Steve,

best to repeat a series of newsgroup emails:

======================================

Very confused current news breaking in London media.
Entire tube system closed due to series of massive explosions - possibly due
to a 'power surge'. Tbe trains have stalled, crashed, been damaged,
certainly many wounded.
Also, reports of a double-decker bus bomb, taking the top off the bus in
Russell Square - fatalities there, apparently.
All very confused reporting currently.
===========================================
Now more (unconfirmed) explosions reported.
On three buses. Plus a pillar box bomb.
Central London is locked solid.
Still no official announcements.
===========================================
London mainline stations now closed.
Incoming trains being halted far out - e.g. Reading.
One bus has certainly been blown out - seen on TV.
'Terrorism' being talked about - 'maybe' etc.
Still absolutely no official announcement, which is very odd.
========================================
Ambulances & buses bringing many wounded into hospitals - but most seem
relatively minor cuts, burns, etc.
More unconfirmed reports of street explosions.
Some fatalities confirmed.
Home Secretary has confirmed some 'terrible injuries'.
Blair due to break off from G8 to give statement shortly.
But still no official statement re causes.
Central London now 'no go', All incoming road traffic being diverted away.
=================================================
The Met Police has confirmed 6 explosions, 5 at varying Underground
locations, one on the bus.
Many injuries confirmed.
All London traffic blocked off, all told not to travel anywhere.
Still no causes.
Blair to talk at Noon BST
=============================================
PM Blair confirms these are a series of terrorist atacks, maybe connected
with G8.
Aspects of London's new multiple terrorist attack plans becoming apparent.
Double-decker buses offloaded passengers and are being used to carry large
numbers of wounded through streets cleared of civilian traffic to hospitals.
Hotels by hospitals being used as mass 'entry wards'.
Very impressive.
=========================================

Surreyman