Nearly two-thirds of people tested in India have shown exposure to Covid-19, a chain of private laboratories said on Wednesday, indicating a runaway spread of the virus as the daily death toll rose to a record 4,529.

India reported 267,334 new daily infections on Wednesday, taking its tally to 25.5 million, the world's second highest after the United States, with a death toll of 283,248, health ministry data showed.