<sod > A woman leans down on Westminster Bridge to help another woman who was injured in this afternoon's attack in London Pieces of a car's undercarriage lay scattered on the pavement of Westminster Bridge as the public went to the aid of victims  Westminster bridge was strewn with injured people who were treated on the road or carried to St Thomas' Hospital  A pedestrian lies stricken on Westminster Bridge after reports a car knocked down people near the Houses Parliament 'London is the greatest city in the world and we stand together in the face of those who seek to harm us and destroy our way of life. We always have, and we always will. 'Londoners will never be cowed by terrorism.' Mr Khan said the capital had suffered a 'horrific attack' which was being treated as terrorism.< eod>< sod >  A woman leans down on Westminster Bridge to help another woman who was injured in this afternoon's attack in London Pieces of a car's undercarriage lay scattered on the pavement of Westminster Bridge as the public went to the aid of victims  Westminster bridge was strewn with injured people who were treated on the road or carried to St Thomas' Hospital  A pedestrian lies stricken on Westminster Bridge after reports a car knocked down people near the Houses Parliament 'London is the greatest city in the world and we stand together in the face of those who seek to harm us and destroy our way of life. We always have, and we always will. 'Londoners will never be cowed by terrorism.' He added: 'My heart goes out to those who have lost loved ones and to everyone who has been affected.< eod>