Vital medical supplies have begun to reach India as hospitals starved of life-saving oxygen and beds turned away coronavirus patients and a surge in infections pushed the death toll towards 200,000.
A shipment from the UK, including 100 ventilators and 95 oxygen concentrators, arrived in the capital New Delhi, although a spokesman for Prime Minister Boris Johnson said the UK had no surplus COVID-19 vaccine doses to spare.
France is this week sending eight large oxygen generating plants and Ireland, Germany and Australia are sending oxygen concentrators and ventilators, an Indian foreign ministry official said, underlining the crucial need of oxygen.
India's first "Oxygen Express" train pulled into New Delhi, laden with about 70 tonnes of oxygen from an eastern state, but the crisis has not abated in the city of 20 million at the epicentre of the latest wave of infections.
"The current wave is extremely dangerous and contagious and the hospitals are overloaded," said Delhi's Chief Minister Arvind Kejriwal, adding that a large public area in the capital will be converted into a critical care hospital.
With frustration mounting, relatives of a recently deceased COVID-19 patient attacked staff with knives at a hospital in the southeast of New Delhi, injuring at least one person, a hospital spokeswoman said.
A video posted on social media showed several people brawling with guards at the same hospital.
Delhi High Court has advised local authorities to provide security at hospitals.
Dr K Preetham, an administrator at the Indian Spinal Injuries Centre, said the oxygen shortage remained a big concern.
"Because of the scarcity (of oxygen), we are forced to put two patients on one cylinder," he said.
The World Health Organisation said it was working to deliver 4000 oxygen concentrators to India, where mass gatherings, more contagious variants and low vaccination rates have sparked the outbreak.
"Many people rush to the hospital, even though home-based care monitoring ... can be managed very safely," its spokesman Tarik Jasarevic told Reuters in an email.
India's 323,144 new cases over the past 24 hours stood below a worldwide peak of 352,991 hit on Monday, while 2771 deaths took the toll to 197,894.
But the fewer confirmed infections were largely due to a drop in testing, health economist Rijo M John, of the Indian Institute of Management in the southern state of Kerala, said on Twitter.
"This should not be taken as an indication of falling cases, rather a matter of missing out on too many positive cases," he said.
Delhi is in lockdown as are the southern state of Karnataka and the worst-hit state of Maharashtra, home to financial capital Mumbai.
A patchwork of curbs, complicated by local elections and mass gatherings such as the weeks-long Kumbh Mela, or pitcher festival, could drive breakouts elsewhere.
About 20,000 devout Hindus gathered by the Ganges river in the northern city of Haridwar on the last auspicious day of the festival for a bath they believe will wash away their sins.
"We believe Mother Ganga will protect us," said a woman on the riverbank, where people bathed with few signs of distancing measures.
India has turned to its armed forces for help as new cases have topped 300,000 since April 21.
Even China, locked in a military stand-off with India on their disputed Himalayan border, said it was trying to get medical supplies to its neighbour.
Prime Minister Narendra Modi has urged all citizens to get vaccinated.
In some cities, bodies were being cremated in makeshift facilities in parks and parking lots, and television channels showed bodies crammed into an ambulance in the western city of Beed as transport ran short.
India has converted hotels and railway coaches into critical care facilities to make up for the shortage of beds but experts say the next crisis will be a lack of healthcare professionals.
The Indian Medical Association also said private hospitals in the western city of Surat would have to shut if they did not get oxygen soon, citing security concerns.
Companies ranging from conglomerates such as Tata Group and Reliance Industries Ltd to Jindal Steel and Power have stepped forward to help supply medical oxygen.
The US Chamber of Commerce has said India's economy, the world's sixth largest, could falter because of the spike in cases, creating a drag for the global economy.
Australia halted direct passenger flights from India until May 15, joining other countries taking steps to keep out more virulent variants.
India, with a population of about 1.3 billion, has a tally of 17.64 million infections but experts believe it runs much higher.