India is the first country to record 400,000 coronavirus cases in a single day

• India reported a record high of 401,993 new cases of COVID-19 on Saturday.
• India's coronavirus surge is overwhelming hospitals and crematoriums, with deaths possibly underreported.
• The surge "will get worse before it gets better," according to one public-health expert.

India's coronavirus surge is getting worse by the day, and it just hit a grim new record.

The nation reported a record high of 401,993 new cases of COVID-19 on Saturday. No other country has breached 400,000 daily cases.

Crematoriums across India are overwhelmed with bodies. Patients are gasping for breath and dying as hospitals run out of oxygen. The country had reported more than 300,000 new cases each day for nine consecutive days before hitting the 400,000 mark.

India also reported more than 3,500 deaths on Saturday - the fourth day in a row that death counts have surpassed 3,000. Those numbers are likely an undercount. A New York Times investigation published this week found "mounting evidence" that suggested fatalities are being "overlooked or downplayed" by the government.

"From all the modeling we've done, we believe the true number of deaths is two to five times what is being reported," Bhramar Mukherjee, an epidemiologist at the University of Michigan, told the Times.

Experts interviewed by Reuters have suggested the death toll could even be between five to 10 times higher than what is being reported. Indian Prime Minister Narendra Modi has not responded to the allegations.

"It will get worse before it gets better," Ashish Jha, a physician and Dean of Brown University's School of Public Health, said of India's outbreak on Twitter on Saturday.

Rapidly spreading coronavirus variants are perhaps the biggest culprit for India's horrific new surge. But a number of other factors also contributed to their spread: massive social gatherings, a slow vaccine rollout, and a healthcare system that was woefully unprepared for the influx of patients.

"This was a collective and shocking policy failure," Jha wrote in an op-ed in the Hindustan Times on Saturday, where he outlined steps he believes India must take "urgently and effectively."

Jha said Indian authorities should move quickly to stop indoor gatherings, implement a nationwide mask mandate, scale up testing, increase supplies of medicines and oxygen, ramp up vaccination efforts, and do more genome sequencing to track COVID-19 variants.

"May is going to be horrible in India. June is going to be hard. If we take the steps outlined here, we are going to see real progress in June, and, by July, things may be meaningfully better," he said. "But if we do these things in a half-hearted manner now, the nightmare that India is living through now will last longer."

The US, which earlier this week pledged to help India produce more vaccines, imposed new travel restrictions on the country because of the coronavirus surge. Friday's move temporarily bars most non-US citizens from entering the United States.

Sophia Ankel and Aria Bendix contributed reporting.