AFP, LONDON: London was braced yesterday for the second shutdown of the Underground within a month as trade unions stage a strike over plans to run Tube trains all night at weekends. The walk-out will last from 6:30 pm (1730 GMT) until Friday morning, causing disruption for millions of commuters and tourists. It will also hit football fans travelling to see English champions Chelsea host Italian side Fiorentina in a friendly game at Stamford Bridge on Wednesday. Overground trains and buses will run as normal. It comes less than one month after a similar strike shut down the Underground network, which handles up to four million journeys every day, for the first time in 13 years in early July. Unions are locked in a bitter dispute with Tube operator London Underground over plans to run trains through the night on Friday and Saturdays from September 12.