Those on the ground in Luxor heard a loud bang reverberate across the ancient landscape and people were seen leaping out of the balloon's basket to the ground.
Hospital worker Yvonne Rennie, from Perth, died and her husband Michael, 49, is in hospital in Egypt.
Another UK national and a British resident who died in the crash were named by sources as Joe Bampton, 40, and his Hungarian-born partner Suzanna Gyetvai, 34, both from London.
Among the dead were also French, Hong Kong, Egyptian and Japanese tourists.
Debris was spread over a wide area after the balloon crash and landed in farmland a few miles from the Valley of the Kings.
Konny Matthews, assistant manager of the nearby Al Moudira hotel, said she heard a boom at 7am local time.
She said: "It was a huge bang. It was a frightening bang, even though it was several kilometres away from the hotel. Some of my employees said their homes were shaking."
Hamdy Shabaan, operations manager at Sinbad Hot Air Balloons, said the basket was on fire when it fell to the ground. It is thought the pilot survived.
Hot-air balloon trips usually take place at sunrise over the pharonic temples at Karnak and Luxor. The early morning flights are supposed to offer the perfect time to see the ancient landscape from above, and other balloons were already airborne when tragedy struck.
Cherry Tohamy, an Egyptian living in Kuwait who was on holiday, was on board one balloon that was landing when she heard an explosion and saw flames from above.
She said: "People were jumping out of the balloon from about the height of a seven-storey building."
Rescue workers gathered the bodies of victims from the field where the charred remains of the balloon, gas canisters and other pieces of wreckage landed.
Tour operator Thomas Cook and the Egyptian authorities launched probes.
It is thought a gas canister used to power the flame that provides the hot air exploded.
An investigator with the state prosecutor's office said the balloon had been landing when a landing cable became entangled around a helium gas tube and a fire broke out on board.
The balloon then rose quickly as hot air filled the canopy before the fire caused the blast.
Serious questions have now been raised over the future of the hot air balloon tour industry in Egypt amid a spate of similar accidents in the past.
Sixteen people were hurt, including two British women, when a balloon crashed during a tour of Luxor in April 2009.
Former policewoman Linda Lea, 67, from Stoke-on-Trent, still suffers from multiple injuries she sustained in that crash.
She said: "I cannot believe this has happened again.
"These balloons are just too unstable. There is not enough training of staff. There were about 22 or 23 in my balloon when it crashed and maybe there were too many then and too many in today's accident."
In 2007, eight French and American holidaymakers and two Egyptians were injured when strong winds blew their balloon off course and sent it plummeting to the ground.
The flights were abandoned for six months while safety was improved.