India on Wednesday reported the highest single daily death toll since the start of the coronavirus pandemic, another grim indicator of the burden borne by the country.

The Ministry of Health recorded 4,529 deaths, though health experts believe this figure could be higher, as the world's second most populous nation reels from a second wave of infections and deaths.

The previous record, according to data from the Johns Hopkins University, was 4,475 deaths set by the United States on January 12.

The ministry also reported 267,334 new daily infections, with daily cases dropping below 300,000 for the third consecutive day.

The second wave of the outbreak in India, one of the worst in the world, erupted in February, overwhelming hospitals and medical staff, as well as crematoriums and mortuaries.

Overall, India has reported 25.4 million confirmed cases and 283,248 confirmed deaths, the second-highest tally globally.

Experts have warned that the official figures for cases and fatalities are significantly lower than the actual figures.

Last week, the World Health Organization declared the variant first identified in India last October was one of "concern at the global level" as there was available information to suggest it transmitted more easily.

As such, the B.1.617 was added to the list containing three other variants of COVID-19 — those first detected in Britain, Brazil and South Africa.

Even though the WHO referenced early studies "suggesting that there is some reduced neutralization", it stressed that it was far too early to interpret that to mean that the variant might have more resistance to vaccine protections.

Indian state leaders have pushed for vaccines to halt the second wave and the devastation it has wreaked, urging Prime Minister Narendra Modi to stop exporting doses, boost production and help them procure urgent supplies from overseas.

(With input from agencies)