India has joined the UK's travel red list - effectively banning travel - as a deadly second wave of infections sweeps the country.
British and Irish nationals can travel to the UK from India, but they must now isolate in a government-approved hotel.
India has seen soaring infection rates, a rapidly rising death toll and the discovery of a new virus variant.
The spike has overwhelmed hospitals, creating a critical shortage of oxygen, intensive care beds and ventilators.
On Friday, India recorded 332,730 coronavirus cases, the highest one-day tally anywhere in the world for the second day in a row. Daily deaths from Covid-19 rose by a record 2,263 in the previous 24 hours.
The rising number of cases has resulted in a deepening healthcare crisis that has gripped several states, and India's top court has asked the central government for a national plan by Friday on bolstering supply, oxygen, medicine, treatment and vaccines.
'Ordeal after ordeal'
Nayan Gangyan is facing a 10-day hotel quarantine when he flies back to London from northern India on Saturday. He travelled to Chandigarh a few weeks ago, when his parents both contracted coronavirus.
He told BBC Breakfast he was left feeling "helpless" in the UK when his father's oxygen levels dropped, there were no beds available in hospital and his mother started to panic.
"It was at that point that I decided 'my family needs help and I need to go back come what may'," he says.
He says the situation in India is "really bad", with the government healthcare system "completely overrun". But they eventually managed to get his father admitted to a hospital where he had previously undergone a liver transplant, and he is doing "much better now".
Now Nayan is preparing to return home to London. "The flight as of now, it's running. I really hope that it does take off," he says.
"I've already booked my quarantine hotel so I'll be going straight there. I'll be landing [then] straight to the hotel and 10 days in the room."
His wife Vani, who has been watching from a distance from their London home, says it has been difficult "not to be able to control or influence" events.
On India's red list status, she says: "We got just over three days' notice so very little time for us to actually affect the outcome or do anything.
"We're just in the position where we have to be okay. After Nayan's ordeal in India he has to go through another ordeal."
Tina Patel and her husband arrived back in the UK on Thursday from Pune, Maharashtra, after travelling to India in March to visit her father-in-law, who was ill due to old age and later died.
She told the BBC people in the city were "desperate" - trying to find hospital beds or a slot in the crematoriums. "We left a city with ambulances wailing away day and night," she said.
"I left broken-hearted as there was nothing we could do but catch the BA flight last night and all we could do was to be thankful that we finally got home."
Friday's travel rule change means direct flights from India are still permitted, but UK and Irish nationals, as well as those with residency rights, must isolate in government-approved hotels - at their own cost - for 10 days.
Travel to the UK is banned for all others who have been in red-list countries in the past 10 days.
There are 40 countries on the government's red list across the Middle East, Africa, Asia and South America. Countries can be added to the list with just a few hours' notice.
Public Health England (PHE) confirmed on Thursday that a further 55 cases of the virus variant first identified in India - known as B.1.617 - were found in the UK in the latest week to 14 April.
PHE experts are currently unsure whether any of the mutations mean the variant can be transmitted more easily, is more deadly or can evade the effectiveness of vaccines or natural immunity.
The final scheduled commercial flight ahead of the rule change - Vistara flight VTI017 - landed at London's Heathrow Airport at 18:48 on Thursday, according to FlightRadar24.
Four airlines asked for a total of eight extra flights to arrive at the west London airport before the 04:00 deadline but were refused permission by airport authorities.
Heathrow bosses are believed to have declined the requests to ensure pressures at the border, reported in recent weeks, were not exacerbated.
Later scheduled arrivals from Delhi and Mumbai to Heathrow, and Delhi to Gatwick Airport, were cancelled on Thursday, airport data showed.
Some of those who arrived before the red list change told the BBC they "couldn't afford to stay away" and "had to get back to work".
"Eventually, yesterday, a friend in the UK managed to book me a ticket from Mumbai to Manchester," Biju Mathew, a social services manager from Walsall, said.
Demand for flights from India to the UK quickly became overwhelming after the government's red list announcement, according to Suresh Kumar, chairman of specialist travel agents Indra Travel.
"A lot of people were hoping that the [UK] government would have made arrangements for people trying to get back," he said. "They were disappointed."
Speaking on Tuesday, Prime Minister Boris Johnson - who cancelled an official visit to India due to take place next Monday - said the addition to the red list was a "purely precautionary" step over a new coronavirus variant.
He said: "What we're seeing in India is a result of a variant under investigation, it hasn't yet been deemed a variant of concern - I think that was why there has been the delay."
The B.1.617 variant was first noted internationally in October and first identified in the UK on 22 February.
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