Travellers in London face a second day of disruption because of a continuing strike by Tube workers in a long-running row over ticket office closures.
Members of the Rail, Maritime and Transport union will end a 48-hour walkout at 9pm tonight, with a further, three-day stoppage planned for next week.
LU said half of train services ran yesterday and two-thirds of Tube stations were open, much more than during a previous strike in February.
Nearly 90% of the usual number of Oyster cards were used on Transport for London's network, according to the company.
But there was still huge disruption to travel, long delays for Tubes and big queues for buses.
The RMT said the strike was "solidly" supported, and the union expects similar backing today.
Picket lines will again be mounted outside Tube stations.
Mike Brown, managing director of London Underground, said 15% more staff worked yesterday than during the previous strike.
He appealed for fresh talks, adding: "Under our plans to modernise the Tube, we are committed to a safe railway with visible staff personally serving our passengers.
"Fairness to our staff is guaranteed - there will be no compulsory redundancies, there is a job for all staff wanting to remain with us and no one will lose pay.
"We have made significant changes to our original proposals after listening to our people and the unions in over 40 meetings.
"The RMT leadership know the real motivations behind their action, but it is infuriating that London's commuters and businesses are the ones who are being forced to pay the price with this unnecessary disruption."
RMT acting general secretary Mick Cash said: "London Underground have dug themselves into an entrenched position and have refused to move one inch from their stance of closing every ticket office, in breach of the agreement reached previously through Acas which enabled us to suspend the previous round of action and in flagrant violation of repeated promises from the London Mayor Boris Johnson that not a single ticket office would be closed on his watch.
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clinlife.co.uk/High_Cholesterol "It is scandalous that Transport for London are blowing what we estimate to be hundreds of thousands of pounds on politically-motivated adverts and propaganda designed to deflect attention from Boris Johnson's broken promises."
Mr Johnson said: "The idea that this is a solidly-supported strike is farcical. This action is the result of a minority of just one union, the RMT, who are refusing to see the logic of what we are trying to achieve."
There were more transport problems in the capital because of fog this morning.
TfL suspended ferry services on the Thames because of poor visibility, saying Thames Clipper tickets were being accepted on local buses and Docklands Light Railway (DLR).
London City Airport in Docklands also reported delays to flights due to poor visibility.