People in India are struggling to register online for a mass vaccination drive set to begin at the weekend as the country's death toll from the coronavirus surged past 200,000, worsened by shortages of hospital beds and medical oxygen.

The second wave of infections has seen at least 300,000 people test positive each day for the past week, overwhelming health facilities and crematoriums and prompting an increasingly urgent response from allies overseas sending equipment.

The last 24 hours brought 360,960 new cases for the world's largest single-day total, taking India's tally of infections to nearly 18 million.

It was also the deadliest day so far, with 3,293 fatalities carrying the toll to 201,187.

However, experts believe the official tally vastly underestimates the actual toll in a nation of 1.35 billion.

"The situation is horrific, absolutely terrible ... Everyone is afraid, every single person. People are afraid that if I am talking to a person, maybe I won't get to talk to them tomorrow or in the near future," New Delhi resident Manoj Garg said.

Delhi state is reporting one death from Covid-19 every four minutes and ambulances have been taking the bodies of victims to makeshift crematorium facilities in parks and parking lots, where bodies burned on rows of funeral pyres.

Genesis hospital in the Delhi suburb of Gurgaon told families to take patients away because its supplies of life-saving oxygen were depleting fast, one family said.

"The hospital is trying to get fresh oxygen but we are told we have to make alternate arrangements," said Anjali Cerejo, whose father had been admitted but now has to try to find another bed elsewhere.

Outside hospitals, people lined up on trolleys, and in cars and cycle rickshaws, with loved ones holding oxygen cylinders for them as they waited for a bed inside.

The World Health Organization said in its weekly epidemiological update that India accounted for 38% of the 5.7 million cases reported worldwide to it last week.

Early modelling showed that the B.1.617 variant of the virus detected in India had a higher growth rate than other variants in the country, suggesting increased transmissibility, it said.

Delhi Chief Minister Arvind Kejriwal said people were falling sick more severely and for longer periods in the second wave, stacking up the pressure on the health system.

"The current wave is particularly dangerous," he said.

"It is supremely contagious and those who are contracting it are not able to recover as swiftly. In these conditions, intensive care wards are in great demand."

Coronavirus patients in India breathe with the help of oxygen under a tent installed along a roadside

Experts said India's best hope is to vaccinate its vast population and today it opened registrations for everyone above the age of 18 to be given jabs from Saturday.

But the country, which is one of the world's biggest producers of vaccines, does not yet have the stocks for the estimated 600 million people becoming eligible, on top of the ongoing effort to inoculate the elderly and people with other medical conditions.

People who tried to sign up said they failed, complaining on social media that they could not get a slot or they simply could not get online to register as the website repeatedly crashed. Even those already eligible were struggling to find doses.

About 9% of India's population have received one dose since the campaign began in January with health workers and then the elderly.

The South Asia head of the International Federation of Red Cross and Red Crescent Societies, Udaya Regmi, said the world was entering a critical phase of the pandemic and needed to have vaccinations available for all adults as soon as possible.

"This is both an ethical and public health imperative," he added. "As variants keep spreading, this pandemic is far from over until the whole world is safe."

The UK has no surplus of coronavirus vaccines to give to India, Health Secretary Matt Hancock said today.

It has given ventilators and oxygen concentrators to India, but Mr Hancock said the UK was currently not in a position to give any vaccines.

"We don't have any excess doses of vaccine in the UK at the moment," he said at a news conference.

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Covid-19 pandemic accelerating, WHO Americas office warns

The Covid-19 pandemic is accelerating, which is why equitable access to vaccines and effective preventive measures are crucial to helping turn the tide, the head of the Pan American Health Organization (PAHO) said.

"Our region is still under the grip of this pandemic ... in several countries of South America the pandemic in the first four months of this year was worse than what we faced in 2020," according to PAHO Director Carissa Etienne.

"This shows that we will only overcome this pandemic with a combination of rapid and equitable vaccine access and effective preventive measures. This pandemic is not only not over, it is accelerating," she added.

Over the past week more than 1.4 million people became infected with Covid-19 in the region and over 36,000 died from complications related to the disease, meaning that one in four coronavirus deaths reported worldwide last week were in the Americas.

Ms Etienne pointed to Canada's infection rates, which surpassed US figures for the first time since the start of the pandemic; surging cases across the Caribbean and Central America, underscoring the expectation of more hospitalisations in Costa Rica as the country reported a 50% jump in cases in the last week; and spiking infections across South America.

The PAHO director urged countries with extra vaccine doses to consider donating them to counties in need in the Americas, saying that considering the increased incidence of Covid-19 variants of concern, time was of the essence.

PAHO serves as the Regional Office for the Americas of the World Health Organization.

Elsewhere, in Brazil, the Senate opened an inquiry into whether Jair Bolsonaro's government committed criminal negligence or corruption in its handling of the pandemic, as the death toll surged to nearly 400,000 and a scramble for vaccines continued.

Mr Bolsonaro has brazenly defied expert advice on the pandemic at virtually every turn, attacking lockdowns, shunning masks, resisting vaccines and touting drugs such as hydroxychloroquine that researchers say are ineffective against the virus.

UK orders 60 million Pfizer Covid-19 shots for booster programme

The UK will buy 60 million more doses of Pfizer/BioNTech's Covid-19 vaccine, Health Secretary Matt Hancock said, in a deal that more than doubles the country's supply of the shot ahead of a booster programme later this year.

The UK has now ordered a total of 100 million doses of the Pfizer vaccine, one of three coronavirus jabs being rolled out.

Mr Hancock said the shots had been secured to support a Covid-19 booster vaccination programme starting in the autumn, adding that the biggest risk to the rollout so far was a new variant of the virus.

Earlier, Public Health England said the details of any booster programme were still being worked out, and it would be designed primarily with new variants in mind.