Prime Minister Narendra Modi sounded the alarm over the rapid spread of Covid-19 through India's vast countryside on Friday, as 4,000 people died from the virus for the third straight day and total infections crossed 24 million.

India is in the grip of the highly transmissible B.1.617 variant of the coronavirus, first detected there and now appearing across the globe. Modi said his government was "on a war footing" to try to contain it.