As India steps up testing to contain the spread of a new mutant strain of coronavirus, first found in the United Kingdom in September, Pune's civic body has put out a video appeal to trace over 100 travellers who returned from the UK before December 22. The Pune Municipal Corporation has also asked the city police to help them. As per news report of NDTV, the civic body's appeal comes as India's tally of patients infected with the mutant strain - believed to be significantly more infectious - rose to 20 this morning.