A Czech zoo on Tuesday burnt 33 kilos (72 pounds) of rare rhino horns, including some it sawed off its own animals in the wake of a brutal attack on a French zoo.
Poachers broke into the Thoiry zoo near Paris in March and killed a critically endangered white rhino, hacking off its horns and putting zoos across the world on high alert.
The brazen attack prompted a zoo in the central Czech Republic city of Dvur Kralove nad Labem to remove and burn the horns from its herd.
"Some of the horns were sawed off after the Thoiry attack, some are from dead rhinos and some came off the animals by accident," zoo spokeswoman Andrea Jirousova told AFP.
At the burning ceremony, Kenyan conservationist Richard Leakey told AFP that the "audacity of entering a zoo in a very civilised part of the world like France is shocking".
"But it shows... that this species is under enormous threat and when you see people around us now with guns, don't for a minute think they're for show," he said after armed police escorted the horns to the ceremony.
Leakey said burning the horns sent a "very clear message. Selling rhino horn makes no sense today".
Black market rhino horn sells for up to $60,000 (50,200 euros) per kilo -- more than gold or cocaine -- with most of the demand coming from China and Vietnam, where it is coveted as a traditional medicine and aphrodisiac.
"We've just got to persuade the people in Vietnam and in Cambodia, in Laos and in China: Listen, if you have problems with sex, chew your fingernails, it's the same product," Leakey said with a chuckle.
Africa's rhinos could be extinct within 15 to 20 years at the rate they are being poached, said Paula Kahumbu, head of Wildlife Direct, a non-profit conservation organisation founded by Leakey in 2004.
"This is a future that we are simply not willing to accept in Kenya," she said.
Dvur Kralove is the world's only zoo to have succeeded in the captive breeding of the extremely rare northern white rhino.
In 2009, it placed three northern white rhinos -- one male and two females -- in the Ol Pejeta reserve in Kenya.
They are the last survivors of this subspecies, but they have not managed to breed.
The zoo said earlier this year experts would try to remove eggs from the two females at Ol Pejeta to save the subspecies by means of in-vitro fertilisation and embryo transfer to surrogate mothers.
The northern white rhinoceros has been nearly wiped out by hunting and poaching for their horns, and by wars in Africa, according to the World Wildlife Fund.