The entire London Underground network was shut down this morning following three explosions on tube trains between Aldgate and Liverpool St, at Edgware Road and between Russell Square and King's Cross. Bus services in the central Zones 1 and 2 are also suspended, as are National Bus coach services in and out of the capital. The Tube will remain closed for the rest of the day, while those travelling by mainline train out of London are advised to check on the current status of services (be patient - website very slow).
Police have confirmed that seven people were killed at Liverpool Street, and that there were 21 fatalities at King's Cross. The current death toll at Edgware Road is five. London's police chief said traces of explosive had been found at one site.
There was also an explosion on a Number 30 bus - travelling from Hackney to Marble Arch - in Tavistock Square, apparently the work of a suicide bomber. Dr Lawrence Buckman of the British Medical Association, whose headquarters is in nearby Tavistock Rd, treated victims at the scene and counted "10 dead, nine critical, nine walking wounded", AP reports.
Emergency services report 45 seriously-injured casualties from all four blasts and around 300 with minor injuries. Alastair Wilson, clinical director at the Royal London, told AP that the hospital had admitted 183 patients from two of the incidents. Eight were critically injured, and six were undergoing surgery. Victims' injuries included general blast and limb injuries, and smoke inhalation.
The Metropolitan Police have issued a casualty hotline number for those concerned about relatives: 0870 1566 344.
Sir Ian Blair, the Metropolitan Police commissioner, urged people to "stay where you are - the whole London transport network is currently stopped. The safest thing is to stay where you are. Don't call the emergency services unless you have a life-threatening situation."
Police have also asked those currently in London to think how and when they will get home, amids fears that an attempted mass exodus from the centre will exacerbate the already chaotic situation.
Those trying to contact friends and family via mobile phone should be aware that network priority may be given over to the emergency services. Vodafone this morning reported congestion, although BT said its network had survived a "massive spike" earlier in the day.
Commissioner Blair further urged the media not to speculate on the cause of the explosions. The BBC, however, reports that "Arab sources said the blasts were probably the work of al-Qaeda"*. Prime Minister Tony Blair confirmed in a live TV statement this lunchtime that it is "reasonably clear" that the explosions were terrorist attacks. For its part, MI5 notes: "It is too early to confirm the cause of the attacks, but the nature of the incident points to a pre-meditated act of terrorism." The PM left the G8 summit in Scotland shortly after his broadcast to travel to London.
The first underground explosion occurred at 0851 BST between Aldgate and Liverpool Street. Further explosions followed between Russell Square and King's Cross (0856) and at Edgware Road (0917).
British Transport Police originally blamed power surges for the blasts, but the National Grid said that "there had been no problems with its system which could have contributed to the incidents".
Eyewitness Tas Frangoullides - who was on the train at King's Cross - told the BBC: "The train didn't get very far out of the station when there was an explosion. Loads of glass showered down over everyone, the glass in the doors in between all the carriages shattered.
"There was a lot of smoke and a lot of dust, there were some areas of panic, I could hear screams. People were trying to work out what happened. A lot of people were covered in blood.
"I started walking towards Russell Square then I saw the bus. Police were running from the scene and waving people away. I had to walk to work because I had to try and do something normal, it was all so chaotic.
"It wasn't till I got to work that I realised I had a cut on my head and my clothes were covered in dust." ®
*The BBC says it has identified an Islamist website on which a posting claims the attacks on behalf of the "Secret Organisation Group of al-Qaeda of Jihad Organisation in Europe".
The statement reads:
In the name of God, the merciful, the compassionate, may peace be upon the cheerful one and undaunted fighter, Prophet Muhammad, God's peace be upon him.
Nation of Islam and Arab nation: Rejoice for it is time to take revenge against the British Zionist Crusader government in retaliation for the massacres Britain is committing in Iraq and Afghanistan. The heroic mujahideen have carried out a blessed raid in London. Britain is now burning with fear, terror and panic in its northern, southern, eastern, and western quarters.
We have repeatedly warned the British Government and people. We have fulfilled our promise and carried out our blessed military raid in Britain after our mujahideen exerted strenuous efforts over a long period of time to ensure the success of the raid.
We continue to warn the governments of Denmark and Italy and all the Crusader governments that they will be punished in the same way if they do not withdraw their troops from Iraq and Afghanistan. He who warns is excused.
God says: "You who believe: If ye will aid (the cause of) Allah, He will aid you, and plant your feet firmly."