Three Brazilian tourists have been killed and more than 20 other people injured after two hot-air balloons collided in Turkey, officials say.
One ascending balloon was torn open as it hit the basket of another, and then plunged to the ground, witnesses said.
The accident happened in Cappadocia, a region popular with tourists for its spectacular volcanic rock formations.
A tourist who was in another balloon said: "It was quite horrific. We looked up and it was falling out of the sky."
Joanne Rowley, an Australian on holiday in Turkey with her husband, added: "It fell straight down to the ground. It was just horrendous.
"You could see that people weren't going to survive. I still feel quite shaken from the experience."
Turkey's civil aviation agency says it has launched an inquiry.
Among the questions expected to be considered is whether too many balloons are taking to the skies in Cappadocia, some 300 kilometres (190 miles) from the Turkish capital, Ankara.
One tourist, E Wayne Ross, said the skies were crowded, and about 100 balloons had taken off early on Monday morning.
Cappadocia, in central Anatolia, is famed for its "fairy chimney" volcanic cones, subterranean cities carved out of soft stone and early Christian churches.
Ballooning has become a popular tourist business in the region over the past decade.
The passengers on board the doomed flight were mostly tourists from Brazil, Argentina and Spain, according to Abdurrahman Savas, the governor of Nevsehir province, who visited the injured in hospital.
He said two Brazilians, aged 65 and 71, had died.
A third Brazilian, aged 76, died in hospital hours later, Turkey's Anatolia news agency reported.
Many of the injured had broken bones.
In 2009, a British tourist was killed and nine other people were injured in a balloon collision in Cappadocia.
In Egypt, a balloon caught fire and crashed in February, killing 19 tourists.