An overnight London Underground strike in protest over the sacking of a Tube driver caused no major disruption.
Members of the Rail, Maritime and Transport (RMT) union went on strike from 9.30pm yesterday until 3.59am and mounted picket lines outside some stations.
London Underground (LU) said it intended to run a good service on all lines but had warned there was a "small chance" of disruption.
A number of passengers said they did not notice any major difference in their journeys.
One traveller wrote on Twitter: "Excellent journey home from Camden to Hornchurch. No disruption to travel at all #tubestrike", while another tweeted: "what tube strike? Haven't noticed any difference".
The union said it was expecting solid support for the industrial action over the dismissal of a driver for failing two alcohol breath tests.
London Underground (LU) said it had zero tolerance towards drugs and alcohol but the union has described its policy as "outdated and flawed".
Nick Brown, LU's chief operating officer, said the strike was "indefensible", adding: "We will not be swayed by it as we will never compromise on the safety of our customers and staff.
"You wouldn't let someone who had been drinking alcohol drive your family in a car, and we don't let people who have been drinking alcohol drive people's families in Tube trains."
John Leach, the union's London regional organiser, said: "LU seem more concerned with defending their flawed policy than they are in treating fairly someone with an unblemished 29-year record.
"The type of machine used to test employees has been known to fail, indeed a failure was recorded last year at Acton depot when a manager tested positive, but the machine was deemed to be faulty. It is LU directors who are defending the indefensible."
