08.49 - Emergency services called to London's Liverpool Street Station after reports of an explosion on the Metropolitan Line between Liverpool Street and Aldgate. Reported as "some kind of power surge".
08.50 - Police called to Aldgate station, east London.
09.22 - King's Cross, Liverpool Street and Aldgate stations cleared.
09.31 - The incident caused major disruption to the entire network with stations across the capital being closed.
09.33 - London Underground said that there has been "another incident at Edgware Road" station in north west London.
09.53 - Mainline train company First Great Western said its services into London's Paddington station were terminating at Reading in Berkshire because of the Underground crisis.
10.00 - The National Grid, which supplies power to the Underground, said there had beenno problems with its system this morning which could have contributed to the incidents.
10.13 - Union officials said their sources had told them there had been at least one explosive device on the Underground. One explosion happened at Edgware Road and there were suggestions of two other explosions at King's Cross and Aldgate.
10.14 - Reports of a bus being ripped apart in an explosion in central London.
10.19 - Mainline services were being halted short of London. The Silverlink company, which normally operates into Euston station, was terminating trains at Watford Junction in Hertfordshire.
10.32 - Mainline London to Scotland train company GNER said it did not expect its East Coast Main Line services to run as far as London at any time today.
11.02 - Home Secretary Charles Clarke confirmed that there had been "terrible injuries" in the explosions across London.
11.24 - Mobile networks report delays for people trying to get through to friends and relatives, after a surge in the volume of calls.
11.30 - Met Police Commissioner Sir Ian Blair said: "We are not aware of any warning at the moment. We have concluded that this is a co-ordinated attack."
11.51 - St Mary's Hospital said it had received four critically injured patients, eight seriously hurt and 14 with minor injuries so far. It could confirm no deaths and had treated no children.
12.00 - Tony Blair says: "It is reasonably clear that there have been a series of terrorist attacks in London."
12.01 - A spokeswoman for University College Hospital in central London, near the scene of the Russell Square bus blast, said: "We have started to receive casualties but we cannot say how many."
12.05 - Reports that the Stansted Express rail service is suspended, although flights are operating normally at Stansted airport in Essex.
12.16 - Emergency services called to Leicester Square underground station, a spokesman for the London Ambulance Service said.
12.21 - More than 100 casualties and one of the dead were taken to the Royal London Hospital in Whitechapel. Three double-decker buses loaded with casualties had brought the injured to the hospital.
12.36 - A British Transport Police spokeswoman said it had no knowledge of any reports of an explosion at Leicester Square.
Can anyone verify that?