The Delhi crematorium where Sanjay acts as a priest is dealing with so many bodies from India's Covid nightmare that it has been forced to expand into an adjacent car park.

"I have lost count," he told AFP of the number of dead brought to the facility.

"We start at sunrise and cremations continue past midnight," he says next to burning pyres and smouldering piles of ash.

Families mourn silently on the roadside of this low-income neighbourhood as they wait the turn of their relatives wrapped in white cloth and garlands of yellow marigolds.

Wailing ambulances regularly bring more bodies. People in homes overlooking the crematorium live with the stench of burning bodies and the cries of grieving families.

India's hospitals are being stretched to breaking point by an explosion in coronavirus cases with people dying outside their doors or at home due to a lack of beds, drugs and oxygen.

Crematoriums are working overtime, their chimneys cracking and iron frames melting from constant use. Wood is reportedly in short supply in places and some families are told to bring their own to burn.

Many crematoriums and graveyards say the official death toll from the virus comes nowhere close to reflecting the additional number of bodies they are dealing with.

For the past three days the crematorium in the Seemapuri area of northeast Delhi has been performing more than 100 funerals a day, and has run out of space.

"We tried to accommodate cremations on the walkways and wherever we could find space but the bodies were coming endlessly," coordinator Jitender Singh Shanty, in a yellow turban, blue hazmat suit and lanyard, told AFP.

"We had to request authorities to allow us to extend the facility to the parking lot," the Sikh says, orange flames licking up off pyres behind him as night falls.

Shanty says they have cremated around 600 bodies since the beginning of the month and that families now have to wait hours to perform the last rites.

"If things don't improve then we might be forced to perform the cremations on the road as there is no space left now."