The Egyptian authorities have suspended all hot air balloon flights near Luxor and launched an investigation following the deaths of 19 tourists in a crash.
Hong Kong, Japanese, British, French and Hungarian nationals were among those killed on Tuesday morning.
A landing rope is reported to have got caught around a fuel gas tube and severed it, after which a fire erupted and the balloon shot up into the air.
It then plunged some 300m (1,000ft) to the ground in a field west of the city.
The pilot and one passenger survived by jumping out of the basket.
Balloon rides are a popular way to see the numerous ancient sites which line the banks of the River Nile at Luxor, in the south of Egypt, such as the temple of Karnak and the royal tombs in the Valley of the Kings.
The balloon which crashed was one of at least nine which took off in a field north of Luxor, on the west bank of the Nile, at dawn on Tuesday.
It was operated by the local company, Sky Cruise, which said a gas cylinder had exploded on board when it was about 300m in the air.
An investigator with the state prosecutor's office told the Associated Press that the balloon had been in the process of landing at around 07:00 (05:00 GMT) when a landing cable got caught around a gas tube and a fire erupted on board.
The balloon then quickly gained altitude before the fire caused the gas canister to explode and it fell to the ground in a sugar cane field outside the village of al-Dhabaa, west of Luxor, an Egyptian security official said.
Mohammed Youssef, a pilot of another balloon which was in the air nearby at the time, told the Guardian newspaper that the fire started when it was 3m from the ground and was caused by a gas leak.
The pilot and a British passenger jumped to safety when the fire erupted, which affected the balance of the balloon, sending more heat into its "envelope" and causing it to climb rapidly, he said. About five or six other people leapt out when it was about 30m off the ground, he added.
"People were jumping out of the balloon from about the height of a seven-storey building," Cherry Tohamy, an Egyptian who was in another balloon, told the BBC. Ambulances arrived 15 minutes later, she said.
Egypt's health ministry said nine tourists from Hong Kong, four Japanese nationals, two British, two French, one Hungarian and an Egyptian had died.
The Hungarian is understood to have been a UK resident, while another Briton is in a stable condition in hospital in the capital, Cairo.
Mr Youssef said he was a close friend of the pilot. He said his father had visited the pilot, who was conscious but had suffered 70% burns.
The governor of Luxor, Ezzat Saad, told the BBC he wanted to send his condolences to the families of those killed and injured.
"We have never seen anything quite like this in Luxor before. It is an awful thing," he said.
"For the safety of the tourists and the Egyptians I have ordered all the companies dealing with balloons to stop flights until we know exactly what happened and the reasons for it."
Civil Aviation Minister Wael al-Maadawi said a committee from the ministry was travelling to Luxor to investigate the incident.
"We cannot say whether this was because of maintenance or human [error] until the investigation committee is completely done with its investigation," he told al-Jazeera TV's Egyptian channel, Mubasher Misr.
The BBC's Aleem Maqbool, who is in Luxor, says there have been concerns about safety since a balloon crashed after hitting a mobile phone transmission tower in April 2009, injuring 16 people, including two British women.
Balloon flights in the area were suspended for six months after the crash while safety measures were tightened up and pilots retrained.