India reported a further decline in new coronavirus cases on Monday, but daily deaths remained above 4,000 and experts said the count was unreliable due to a lack of testing in rural areas.

Even as new Covid-19 infections have shown a declining trend, credit rating agency Crisil on Monday said it is “too early” to say that the second wave of the pandemic has peaked and flagged concerns over the vaccination drive.

After opening up the vaccination for all adults, the drive has suffered because availability of vaccines has become a “national bottleneck”, the rating agency said in a report.

Daily addition of infection touched 4.14 lakh on May 6, and declined to an average of 3.6 lakh a day for the week ended May 16. The new cases dropped below 3 lakh for the first time in about a month only on Monday to 2.81 lakh.

The decline in new cases offers some respite, but, “it's too early to call a peak”, the report noted.

"There are still many parts of the country which have not yet experienced the peak, they are still going up," said World Health Organization Chief Scientist Soumya Swaminathan, who also pointed to the "very high" national positivity rate, at about 20 per cent of tests conducted, as a sign that there could be worse to come.

"Testing is still inadequate in a large number of states. And when you see high test positivity rates, clearly, we are not testing enough. And so the absolute numbers actually don't mean anything when they are taken just by themselves; they have to be taken in the context of how much testing is done, and test positivity rate."

The Crisil report similarly acknowledged that the new cases have fallen without a dip in testing numbers.

“India's Covid-19 affliction curve has turned for the first time since the second wave began, with daily cases in the week ended May 16 falling 15 per cent sequentially,” it said.

“While vaccination was opened to all adults two weeks back to battle the fierce second wave, vaccine availability has become a national bottleneck,” it said.

As a result of this, some states have announced a temporary halt to their vaccination drive for the 18-44 age group and prioritised those in the 45 plus bracket, especially the second doses, it added.

Having begun to decline last week, new infections over the past 24 hours were put at 281,386 by the health ministry on Monday, dropping below 300,000 for the first time since April 21. The daily death count stood at 4,106.

At the current rate India's total caseload since the epidemic struck a year ago should pass the 25 million mark in the next couple of days. Total deaths were put at 274,390.

It is widely accepted that the official figures grossly underestimate the real impact of the epidemic, with some experts saying actual infections and deaths could be five to ten times higher.