The UK strain is driving the Covid surge in Delhi, an analysis of samples has revealed. Data released by the National Centre for Disease Control (NCDC) says over 400 cases of the UK strain and 76 of the Indian double mutant were found in Delhi. Some 11 per cent samples from across India show "variants of concern". A total of 1,644 cases of the UK strain have been found in India, 112 cases of the South African strain, one of the Brazilian strain and 732 cases of the double mutant that emerged in India.