India has become the first country to report more than 400,000 new coronavirus cases in a single day, as its nationwide vaccine drive launches amid a supply crisis.

Some 3,523 deaths were officially recorded in the past 24 hours - but the real figure is thought to be far higher as many fatalities go unreported.

All adults in India are now eligible to be vaccinated.

But several states say they do not have the doses to carry out the exercise.

India had previously focused on vaccinating frontline workers and the over-45s. The country is facing acute shortages of medical oxygen and hospital