Why is India seeing such a huge surge in Covid-19 cases?

A double mutant' strain, lack of medical supplies and the relaxation of lockdowns have combined to foment disaster

India has seen a terrifying increase in coronavirus cases in the past few weeks. Monday saw another new record when the country racked up 273,810 new cases, with no sign that the surge is abating.

The capital, New Delhi, was placed in lockdown for a week from Monday, and Maharashtra state, the centre of the surge and home to the financial capital, Mumbai, further tightened restrictions on shops and home deliveries from Tuesday.