8.51am: Seven people are killed in an explosion on a Circle or Central line train 100 yards from Liverpool Street Underground station. The blast happens in the region of Moorgate, Liverpool Street and Aldgate stations.
8.56am: A total of 21 people are killed following a blast on the Underground close to Russell Square and King's Cross stations.
9.15am: First report from the Press Association of emergency services called to London's Liverpool Street Station to reports of an explosion
9.17am: Five people are killed in an explosion at Edgware Road Underground station. Police said a blast ripped through a carriage, a wall and into two other trains.
9.24am: British Transport Police say there are reports of one person suffering a life-threatening injury and several "walking wounded".
9.33am: All London Underground services are suspended - the network says it as the result of a power fault across the network.
9.33am: London Underground tells the Press Association there has been "another incident at Edgware Road" station.
9.40am: British Transport Police say power surge incidents - some causing explosions - have occurred on the Underground at Aldgate, Edgware Road, King's Cross, Old Street and Russell Square stations.
9.47am: An unknown number of people die when an explosion tears through the back of the number 30 Hackney to Marble Arch bus. The blast happens at the junction of Woburn Square and Tavistock Place.
10.00am: The National Grid, which supplies power to the Underground, confirms there have been no problems with its system.
10.02am: Scotland Yard says its officers are assisting with what has been termed a "major incident" and confirms there have been casualties.
10.10am: It is confirmed that Prime Minister Tony Blair is being updated on the chaos in the capital between meetings with heads of state at the G8 Summit in Gleneagles.
10.13am: Union officials tell the Press Association that they have been told there has been at least one explosive device on the Underground.
10.14am: Eyewitness Belinda Seabrook tells the Press Association how she saw an explosion rip though a bus as it approached Russell Square.
10.21am: Scotland Yard confirms there have been "multiple explosions" in London.
10.23am: British Transport Police confirm there has been an explosion on a bus in Tavistock Square.
10:26am: Scotland Yard confirm the bus blast, but do not know the cause of the explosion.
10:28am: London Fire Brigade says it had been called to reports of "explosions" at a number of locations in central London, including Aldgate, Edgware Road and Tavistock Square as well as to another incident at King's Cross.
10:39am: All London hospitals are put on major incident alert.
10:46am: A passenger on the train which exploded at Edgware Road reveals how he saw several bodies in the wreckage.
10:51am: London Ambulance Service confirms it is only sending ambulances to patients across the capital with life-threatening illnesses or injuries.
10:53am: Home Secretary Charles Clarke says the blasts have caused "terrible injuries".
10:56am: Commons leader Geoff Hoon tells MPs ministers were assessing and clarifying the situation. He confirms were emergency talks are ongoing about the explosions.
11:00am: Members of the public are told not travel to London following the blasts.
11:02am: Speaking outside 10 Downing Street, Mr Clarke confirmed that the COBRA civil emergencies committee of senior ministers had met and said police had taken "operational command" of the situation.
11:08am: All bus services in central London have been suspended, Transport for London announce.
11:12am: Charing Cross Road in central London is cordoned off between Cambridge Circus and Centre Point after a report of a suspect package at a bus stop.
11:16am: Metropolitan Police Commissioner Sir Ian Blair says there have been at least six explosions, but claims the picture is still " very confused".
11:24am: Mobile phone operators confirm networks are jammed as anxious callers attempt to contact loved-ones.
11:26am: President of the European Parliament, Josep Borrell, claims terrorists are behind the "co-ordinated series of attacks" and "confirmed deaths".
11:27am: Police sources at the scene at Aldgate say there are unconfirmed reports of two fatalities.
11:30am: Motorists outside the capital are warned not to enter by motorway signs, which read: "Avoid London. Area closed. Turn on radio".
11:32am: Sir Ian Blair says he is concerned there has been "a co-ordinated attack" and confirms there is evidence of explosives at least one of the explosion sites.
11:38am: City of London police confirm there have been two deaths at Aldgate.