The intensity of the flames from the crash of Air India Flight 171 has made the identification of passenger remains a mammoth task, medical officials in India said on Sunday, as relatives of more than 200 victims waited outside a mortuary for a third day.

The Boeing 787-8 Dreamliner was carrying 125,000 liters, or more than 33,000 gallons, of fuel when it crashed on Thursday, a full load for a nearly 10-hour flight from Ahmedabad to Gatwick Airport near London.

Senior health officials in Ahmedabad told a visiting delegation on Saturday that initial findings indicated that temperatures at the crash site had reached 1,500 degrees Celsius, or 2,700 degrees Fahrenheit, according to two people who attended the briefing. Such temperatures are more than enough to incinerate bodies.

H.P. Sanghvi, the director of the forensic lab where most of the DNA samples are being sent, told the Indian news media that the damage to the bodies made collection and testing difficult.

“These high temperatures affect the DNA present in various parts of the body,” Mr. Sanghvi said. “This process is very complex.”

By Sunday evening, only 35 bodies had been handed over to relatives, among an overall official death toll of 270 from inside the plane and on the ground.