Ashitha Nagesh
BBC News, London

Prof Anup Malani from University of Chicago led a study during the first wave of the virus last year looking at under-reporting of cases and deaths in Karnataka.

He found that the state alone had had more than 31.5 million cases by the end of August 2020. The official figure for the whole of India at that point was only eight million.

He tells me that Karnataka is having the same issues with under reporting that it had then - particularly in rural areas, where there are fewer testing facilities.

He says world health officials need to do population-level surveillance. "It’s like weather stations - we test for weather and pollution not just in the places where there are crises but all over the place.”

Prof Malani adds that India “doesn’t have a great death-reporting registry system” - something, he says, officials should consider improving before a third wave hits.

India currently has the biggest demand for oxgyen out of all countries hit by the pandemic. Nearly 90% of the country's oxygen supply - 7,500 metric tonnes daily - is being diverted for medical use.

Here’s a map laying out how India compares to the other global hotspots in Brazil or Iran. None of those other countries has so far experienced an oxygen crisis like we’re seeing in India at the moment.

Image source, Getty Images

A earthquake has hit the Indian state of Assam as the country battles a devastating Covid wave.

The 6.4 magnitude hit Assam this morning, causing widespread damage in the northeast state. No deaths have so far been reported.

Healthcare facilities including Dispur Hospital, Apollo Clinic, Down Town Hospital and Excelcare Hospital were all damaged, the Press Trust of India reports - hindering services.

People also escaped their homes and other buildings in panic, which affected social distancing and other virus measures in the area.

Priyanka Gandhi Vadra, leader of India's main opposition Congress party, said: "To my sisters and brothers in Assam who are now dealing with the double blow of an earthquake and the rampaging second wave of Covid, I send you my love and prayers."

Image source, PA Media

The Prince of Wales says he has been "deeply saddened" by the impact of coronavirus on India, after the country's Covid death toll passed 200,000.

In a newly-released statement, Prince Charles highlights the charitable efforts of the British Asian Trust and its emergency appeal, and calls on people to help in any way they can.

"I have been deeply saddened by the tragic images we have all seen as Covid-19 takes its horrific toll in India," he says.

"Like many others, I have a great love for India and have enjoyed many wonderful visits to the country.

"Indian aid and ingenuity has been a support to other countries through this immensely difficult time. As India has helped others, so now must we help India."

He adds: "If I may, I would also want those suffering the effects of this pandemic in India to know that they are in my thoughts and prayers.

"Together, we will win this battle."

Arvind Chhabra
BBC Punjabi, Chandigarh

For the first time this year, the virus's daily death toll touched 100 in the northern state of Punjab on Tuesday, along with a new case tally of nearly 6,000.

The day's news is grim. "With one in 10 Covid patients needing critical care, city runs out of beds," reads one newspaper headline. Here's what some others say:

"8 civil hospitals, zero ventilator in Fatehgarh"

"Patiala hospital sees 31 deaths in 24 hours"

"Vaccination for all above 18 in Punjab may get delayed"

There are nearly 52,000 active coronavirus cases among the state's 28 million inhabitants, with 677 patients on oxygen support.

The government claims there is no shortage of oxygen in public hospitals, but people are struggling to find oxygen and are being forced to buy it on black market.

Starting Tuesday, the state imposed a night curfew from 18:00 to 05:00, and a complete lockdown at weekends. That means everything will be shut, except government offices and essential services.

Image source, Getty Images

Will Fyfe
BBC News

A group of Indian students are asking their university to defer fees so the money can be used to help family back home overwhelmed by Covid-19.

The Cardiff Metropolitan University students say they feel "helpless" and "panicked" watching from the UK.

The university said it could not comment on individual cases but would continue to support students.

Several students who spoke to BBC Wales said they owed thousands of pounds in fees by the end of this month, which their families could no longer afford to pay.

They said they wanted to be able to use any immediate cash to help their families with medical supplies and food.

"A few months back I lost my dad to the Covid situation," said Kylash Indla, who is studying data science.

"Mum was a teacher and dad was a doctor," he explained.

"After the passing of dad, my mum is now not getting any wages. She was a private teacher, so she is now not getting any wages and there is no funding for my family.

"Everything is shut down, there is no income source, there is nothing."

Mr Indla said he felt family members in India did not want to burden him with how bad things had become, but he had heard of some relatives dying due to problems with oxygen supplies.

Read more here.

Image source, EPA

From today, everyone in India over the age of 18 can register to have a Covid vaccine - so it's no surprise there's been a huge surge in people searching for the registration site.

According to Google Trends, there have been between one million and five million searches for "CoWIN".

CoWIN is the name of the government portal where people can book to have a Covid vaccine.

You can either book your vaccine through the CoWIN website itself, external - although it appears to have crashed - or you can register on the Aarogya Setu mobile app.

Vikas Pandey
BBC News, Delhi

With hospitals in Delhi and many other cities running full, families have been forced to find ways to treat Covid patients at home.

So, many of them have turned to the black market, where prices of crucial drugs such as remdesivir and tocilizumab, and oxygen cylinders, have skyrocketed. But even then supply is no guarantee.

I know a family that cobbled together money to buy the first three doses of remdesivir from the black market, but couldn’t afford to get the remaining three as prices shot up further. The patient continues to be critical.

Another family took a while to find the money because of the high price and by the time they did, the drug was sold out. They are still searching as the patient continues to deteriorate.

Take a look at the graph below from our investigation. It’s frightening to see how much black marketeers are profiteering.

Most Indian families can’t afford these prices and they watch their loved ones sink without getting crucial drugs.

I have heard this story dozens of times in the past 10 days. While ministers insist that there is no shortage of drugs, the reality on the ground is very different.

Image source, Reuters

IT firms in Bengaluru, Chennai, Hyderabad and other Indian cities run backroom operations for some of the world's biggest financial firms, including Goldman Sachs and Standard Chartered.

Now, these banks are setting up Covid "war rooms" in a bid to secure oxygen, medicine and hospital beds for their workers in India.

Reuters news agency reports they have the infrastructure in place to vaccinate thousands of employees and their families when age restrictions are lifted next month.

It adds that workers at huge tech firms like Accenture and Wipro say teams are working up to 14 hours a day and struggling to deliver on projects as staff call in sick and take time off to care for friends and relatives.

Hospitals across India have been plagued by a string of accidents, fires, and oxygen leaks, amid what is already a bleak situation.

At Zakir Hussain Hospital in the city of Nashik, 24 people died after an oxygen leak. At another incident in Mumbai, another hospital caught fire, leaving 11 people dead. All this is happening at a time when India is already struggling to cope, as the BBC Marathi's Anagha Pathak reports.

Shruti Menon
BBC Reality Check, Delhi

Image source, Getty Images

The US is helping India with crucial raw materials for vaccine production, after India's biggest vaccine maker, the Serum Institute of India, complained of shortages of specialised imports from the US.

In India, less than 10% of the population has so far received an initial Covid vaccination, and with cases and deaths continuing to surge, ensuring supply is becoming an increasingly important issue.

But does India have the capabilities to meet that demand?

The BBC Reality Check team has investigated that here.

Image source, Reuters

Along with beds and oxygen, Indian social media timelines are full of appeals for the antiviral drug remdesivir. It first gained greater attention when former US president Donald Trump revealed he had received it.

It was developed as a treatment for Ebola, and works by confusing the virus as it looks chemically similar to some of the raw materials the virus needs to replicate. This disrupts the virus’s ability to make thousands of copies of itself.

Indian doctors have been prescribing remdesivir for seriously ill patients and demand is so high that vials are being sold for many times the market price. But there is fierce debate about its effectiveness.

India has approved it for emergency use but the World Health Organization has found it has little to no effect on Covid patients’ chances of survival.

Read more about the controversial drug here.

Yogita Limaye
BBC South Asia correspondent

Everywhere I’ve gone over the past few days - hospitals, crematoriums - I’m seeing increasing anger against the government. Rati Gadgil was driving around with her mother in the back of her car, trying to find a hospital bed.

"They come to us when they want our votes, and now when we are dying in the streets... Where are they?" she asked me, tears rolling down her face.

One hospital I visited only had a few hours of oxygen left. "We’re only getting assurances from the government, no oxygen," a doctor said.

For one son outside a hospital, it's been an excruciating waiting game. "My father doesn’t know what’s going on. He’s in there thinking it’s all ok and that he will be out soon. But we’re living in fear every minute that oxygen will run out. It is my basic right. What is the government doing?"

Image source, Getty Images

Geeta Pandey
BBC News, Delhi

Image source, Reuters

The chief minister of Uttar Pradesh, Yogi Adityanath, is trending on Twitter with nearly 22,000 tweets since the morning.

It came after reports that his government had ordered the police to open an investigation against a man who’d sought an oxygen cylinder for his sick grandfather on social media.

He did not mention Covid-19.

His 88-year-old grandfather has since died, but police have accused him of “circulating a rumour with an intent to cause fear or alarm during a pandemic.”

As the virus has spread across the state in the past few weeks, the state government’s handling of the crisis has come in for severe criticism, with many saying the authorities have left people to die.

Goa has become the latest state to announce a lockdown.

Officials said the strict four-day lockdown would last from Thursday night until Monday morning. Many states have announced similar measures as Covid cases surge.

“If people do not step out for the next four days we will be successful in breaking the chain of this surge,” Goa's Chief Minister Pramod Sawant told local media.

Essential services will remain open, while bars will be shut and restaurants will only be open for deliveries. Tourists will not be allowed out of their hotels for the four-day period.

Goa - famous for its beaches and parties - saw a huge influx of local tourists in February and March when cases were low.

Image source, Getty Images

India's Prime Minister Narendra Modi has seen a barrage of criticism in recent days.

An opinion piece in today's Telegraph newspaper, external did not mince its words, saying "Narendra Modi needs to go."

It isn't alone in its sentiment - an opposition politician has accused him and his government , externalof ignoring scientific warnings to participate in election rallies and allow a massive Hindu festival in northern India.

Dr Navjot Dahiya, the vice president of the Indian Medical Association, called him a "super spreader", external who had "tossed all Covid norms in the air."

#ResignModi was even trending on Twitter earlier this week.

State governments, from Delhi to Karnataka, have also been criticised for allowing Covid protocols to lapse and failing to prepare for what epidemiologists say was an inevitable surge.

But the focus is on Mr Modi, who centralised much of the Covid response, and boasted of his government beating the pandemic - until the second wave arrived.

Roxy Gagdekar
BBC Gujarati, Ahmedabad

It's not a hopeful picture in the Indian state of Gujarat, which is governed by India's ruling Bharatiya Janata Party (BJP).

Cases and deaths have been steadily rising - it had added about 14,300 cases and 170 deaths in 24 hours as of Tuesday night. But the numbers, especially the death toll, could be far higher since local news reports have contradicted official figures for weeks now.

Just getting hold of an ambulance is a demanding task - it takes between two to 48 hours just to book one through the emergency hotline.

And they have no other choice - should they arrive in a private vehicle, they are not admitted. As a result, some people have died outside hospitals.

Despite all this the government has refused to implement a lockdown, saying there is no scientific basis to prove that lockdowns stop the spread of the virus and that lockdowns harm the economy.

Pradip Mazumder
Contributor Maryland, US

Image source, Supplied

It was the evening of 19 April when I got a call from my nephew, telling me that my mother's oxygen level had fallen.

We called at least 15 different hospitals in Kolkata (formerly Calcutta) ‑ only to hear that they were completely filled. We finally got a confirmation from a private hospital that they had a bed and oxygen available.

Days later, we were told that her condition had stabilised and were handed a Covid report - which said that while she tested positive, the interpretation was "inconclusive". We tried to speak to a doctor, but he was not available.

We had no choice but to move her to a government hospital. There, the visiting doctor told us that she had developed pneumonia and also her blood oxygen level was quite low. My incredibly soft spoken and kindhearted mother left us an hour after that.

I felt helpless and frustrated while trying to handle this situation from abroad. I felt the government should have done more to hold the private hospitals accountable - particularly those primarily focused on making money.

Geeta Pandey
BBC News, Delhi

Image source, Rukmini Kumar

Rukmini Kumar, who tested positive for the new strain of coronavirus last Wednesday, posted this photograph after “meeting” her 14-year-old daughter on Sunday.

She escaped the virus last year when her entire family – parents, husband and daughter – were infected.

“More than the discomfort and the pain of the disease, being away from my child hurts me the most. I’m quarantining in one part of the apartment and she can only see me though the glass door and we talk on the phone," Ms Kumar told me.

"I can sense her worry, I can see it in her eyes. She keeps asking me,‘how are you?’ Today, I told her I’m much better and I could see her eyes light up.”

It's a grim situation across all of India, but the western state of Maharashtra - and its capital Mumbai - have been hit especially hard.

The state has been at the epicentre of India's second virus wave - accounting for more than a quarter of India's cases.

And just this morning, it was hit by more bad news - a fire broke out at a private hospital, leading to the deaths of four people.