London Underground strike causes severe disruption
Limited services are operating on most London Underground lines after the first in a series of 24-hour strikes crippled the network.
Millions of Tube passengers faced major disruption as services on all but the Northern Line were suspended or delayed for most of the morning rush hour.
Staff walked out in two waves at 1700 BST and 2100 BST on Monday in a row over 800 job cuts.
Unions said support for the action was "rock solid".
Maintenance staff walked out first on Monday, followed by drivers, signallers and station staff four hours later.
The strike was due to finish at 2100 BST on Tuesday, but Transport for London (TfL) said there would be some disruption throughout the rest of the night.
TfL said it hoped services would be running fully on Wednesday.
It added that on Tuesday almost 40% of its trains were running and only the Circle Line was completely suspended.
A full service has been operating on the Northern Line but many stations on the line are closed.
A full service began operating on the Waterloo and City Line during the latter part of the morning rush hour.
The Bakerloo, Victoria, District, Central, Piccadilly, Hammersmith and City, Jubilee and Metropolitan lines are all partly suspended and more than 70 stations remain closed.
The Rail Maritime and Transport (RMT) and the Transport Salaried Staffs Association (TSSA) unions are fighting London Underground (LU) plans to scrap 800 jobs in Underground ticket offices.
The unions have said security could be compromised for passengers.
But LU has insisted all stations will still be staffed and pledged there would be no compulsory redundancies.
Standing on the picket line at King's Cross station, general secretary of the RMT union Bob Crow apologised to commuters but warned that more strikes could be on the way.
He said: "The message to the mayor and his transport officials is clear - stop playing fast and loose with safety, stop the drive towards unstaffed stations, drop the threat of these lethal cuts and start meaningful talks on a safe and secure future for the London Tube system."
The RMT has also accused LU of breaching safety regulations during the strike, but the Office of Rail Regulation said it was satisfied with LU's arrangements.
TfL said while there was disruption, people were able to travel around the city because of its contingency plans for dealing with the industrial action and it would be reviewing the situation hour-by-hour.
Mike Brown, of LU, said: "We are doing everything possible to keep as many Tube services operating today, and to keep Londoners moving.
"Londoners will face some disruption, but the city is not paralysed and people will still be able to get around."
An extra 100 buses and 10,000 more passenger journeys on Thames riverboat services have been laid on. Some taxi ranks are being marshalled and escorted bike rides are operating.
A TfL spokesman said there had been an extra 2,000 completed journeys using the city's cycle hire scheme between 0800 BST and 0900 BST, compared to the same time on Monday, a rise of about 60%.
But outside Kings Cross station in central London, frustrated commuters gathered, trying to work out how to get to work by alternative means.
Zeubair Latif, 23, from Gants Hill, in east London, who had just finished working a night shift stocking shelves at St Pancras' M&S store, said: "It's a joke. It affects a lot of people."
Sarah Fenton, 34, from Hertford, said: "We're being held to ransom by the strikers.
"It's unfair on the public who are trying to get to work so we don't lose our jobs."
'Keep pressure up'
The director of the Greater London Group at London School of Economics, Tony Travers, said the unions and Tube bosses have a "difficult and awkward" relationship.
"The Tube unions know that the Underground is a public service and it can't go bankrupt and it has a buoyant demand and so they are in a very good position to keep the pressure up.
"And the politicians who stand behind the management have never seen fit to try to sort this out once and for all," he added.
London Mayor Boris Johnson cycled to the Stock Exchange in the City to speak at the opening session of the Capital Markets Climate Initiative.
Mr Johnson said new staffing proposals for the Underground were "moderate and sensible" and accused the unions of "cynically deciding to try the patience" of commuters.
Mr Brown, of LU, said: "Londoners will doubtless find it incredible that the two union leaderships are pursing this action when they have been given cast-iron assurances that the staffing changes we are making come with no compulsory redundancies."
The RMT and TSSA has further action planned for October and November.
Commuters suffered further disruption when rail services into London were affected after a lorry crashed into a railway bridge at Haslemere in Surrey.