Many medical experts, opposition leaders and some Supreme Court judges say a strict lockdown is the only option, as the virus rages in cities and towns, hospitals are forced to turn patients away and crematoriums struggle to handle the dead.

On Friday, India recorded 414,188 confirmed cases in 24 hours, a new record. Its total tally has risen to more than 21.4 million since the pandemic began. The Health Ministry also reported 3,915 additional deaths, bringing the total to 234,083. Experts believe both figures are an undercount.

Over the past month, nearly a dozen out of India's 28 federal states have announced less stringent restrictions than the nationwide lockdown imposed for two months in March last year.

Modi, who held consultations with top elected leaders and officials of the worst-hit states on Thursday, has so far left the responsibility for fighting the virus to poorly equipped state governments.

Dr. Randeep Guleria, a government health expert, said a complete, aggressive lockdown is needed in India just like last year, especially in areas where more than 10 per cent of those tested have contracted COVID-19.

Srinath Reddy, president of the Public Health Foundation of India, acknowledged that different states were experiencing different intensities of the epidemic, but said a "coordinated countrywide strategy" was needed.

Anthony Fauci, President Joe Biden's chief medical adviser, also suggested a complete shutdown in India may be needed for two to four weeks to help ease the surge of infections.

"As soon as the cases start coming down, you can vaccinate more people and get ahead of the trajectory of the outbreak of the pandemic," Fauci said in an interview with the Indian television CNN News18 news channel on Thursday.

He said it appears there are at least two types of virus variants circulating in India. He said B117, which is the UK variant, tends to be concentrated in New Delhi and that the 617 variant is concentrated in the worst-hit western Maharashtra state.

"Both of those have increasing capability of transmitting better and more efficiently than the original Wuhan strain a year ago," Fauci said.

Modi imposed a two-month lockdown last year on four hours' notice. It stranded tens of millions of migrant workers who were left jobless and fled to villages with many dying along the way. Experts say the decision helped contain the virus and bought time for the government.

India's economy contracted by 23 per cent in the April-June quarter last year and showed recovery as the restrictions were eased. The International Monetary Fund's projection of 12.5 per cent growth in 2021-22 financial year, beginning April, is expected to suffer again with the surge in infections.

Modi's policy of selected lockdowns is being supported by some experts, including Vineeta Bal, a scientist at the National Institute of Immunology. She said different states have different needs, and local particularities need to be taken into account for any policy to work.

Dr.Yogesh Jain Ganiyari of the Peoples Health Support Group, a public health program, said lockdowns were the most effective way of curbing infections, but authorities needed to take into account the humanitarian aspect.

"But we don't live in a lab" said Ganyari. "Those who look at lockdowns just as disease control mechanisms are heartless. You have to think about the people."

Australian Associated Press