Safety on the London Underground The earliest attack on the London Underground was in 1885, when a bomb exploded on a Metropolitan line train at Euston Square station. The Provisional IRA (and its predecessors) carried out over ten separate attacks between 1939 and 1993. As a response to growing 'Mumbai-Style' terrorist attack threats, the British Transport Police has its own detachment of armed officers who will regularly patrol both the Underground’s stations and its trains. Various regulations aim to improve safety on the Tube. Smoking was allowed in certain carriages in trains until 9 July 1984. In the middle of 1987 smoking was banned for
London Underground Electronic ticketing in the form of the contactless Oyster card was introduced in 2003. London Underground services on the East London line ceased in 2007 so that it could be extended and converted to London Overground operation, and in December 2009 the Circle line changed from serving a closed loop around the centre of London to a spiral also serving Hammersmith. Since September 2014, passengers have been able to use contactless cards on the Tube. Their use has grown very quickly and now over a million contactless transactions are made on the Underground every day. The Underground serves 270 stations.