Mourners covered white coffins with flowers in India on Sunday as funerals were held for some of at least 279 killed in one of the world's worst plane crashes in decades.

Health officials have begun handing over the first passenger bodies identified through DNA testing, delivering them to grieving relatives in the western city of Ahmedabad, but the wait went on for most families.

"They said it would take 48 hours. But it's been four days and we haven't received any response," said Rinal Christian, 23, whose elder brother was a passenger.

There was just one survivor out of 242 passengers and crew on board the Air India jet when it crashed Thursday into a residential area of Ahmedabad, killing at least 38 people on the ground.

"My brother was the sole breadwinner of the family," Christian told AFP. "So what happens next?" 

At a crematorium in the city, around 20 to 30 mourners chanted prayers in a funeral ceremony for Megha Mehta, a passenger who had been working in London. 

As of Sunday evening 47 crash victims have been identified, according to Rajnish Patel, a doctor at Ahmedabad's civil hospital. 

"This is a meticulous and slow process, so it has to be done meticulously only," Patel said Saturday.

One victim's relative who did not want to be named told AFP they had been instructed not to open the coffin when they receive it.

Witnesses reported seeing badly burnt bodies and scattered remains.

Workers went on clearing debris from the site on Sunday, while police inspected the area.

The Boeing 787-8 Dreamliner erupted into a fireball when it went down moments after takeoff, smashing into buildings used by medical staff.

The majority of those injured on the ground have been discharged, Patel said, with one or two remaining in critical care.

'We need to know'

Indian authorities are yet to detail the cause of the disaster and have ordered inspections of Air India's Dreamliners.

Aviation Minister Ram Mohan Naidu Kinjarapu said Saturday he hoped decoding the recovered black box, or flight data recorder, would "give an in-depth insight" into what went wrong.

Imtiyaz Ali, who was still waiting for a DNA match to find his brother, said the airline should have supported families faster.

"I'm disappointed in them. It is their duty," said Ali, who was contacted by the airline on Saturday. 

"Next step is to find out the reason for this accident. We need to know," he told AFP.

Just one person miraculously escaped the wreckage, British citizen Vishwash Kumar Ramesh, whose brother was also on the flight.

Air India said there were 169 Indian passengers, 53 British, seven Portuguese and a Canadian on board the flight, as well as 12 crew members.

Among the passengers was a father of two young girls, Arjun Patoliya, who had travelled to India to scatter his wife's ashes following her death weeks earlier.

"I really hope that those girls will be looked after by all of us," said Anjana Patel, the mayor of London's Harrow borough where some of the victims lived.

"We don't have any words to describe how the families and friends must be feeling," she added.

While communities were in mourning, one woman recounted how she survived only by arriving late at the airport.

"The airline staff had already closed the check-in," said 28-year-old Bhoomi Chauhan.

"At that moment, I kept thinking that if only we had left a little earlier, we wouldn't have missed our flight," she told the Press Trust of India news agency.

by Aishwarya Kumar