LONDON ? London's subway drivers have walked out over a pay dispute, causing trouble for thousands of shoppers out to take advantage of the traditional Boxing Day sales.
Transport for London has warned that shoppers seeking out bargains at the capital's shopping centers face "severe disruption." Several Underground lines have been suspended, and limited services are operating on the rest of the subway network.
The ASLEF union is staging the one-day strike to demand for extra pay for members working on the public holiday.
Despite the disruptions, large crowds of shoppers started flooding department stores in London and other British cities as soon as doors opened early Monday.
The union plans to stage three more strikes in January and February if the dispute is not resolved.