Fourteen orangutans that were smuggled out of Indonesia and believed to have been put to work at tourist attractions in Thailand were sent home on Thursday.

Indonesia's air force sent a C-130 plane to transport the apes, each in a metal cage, for the five-hour trip from Bangkok to Jakarta, the Indonesian capital.

Most of the orangutans were rescued six years ago on the resort island of Phuket and were sent to an animal sanctuary and breeding center outside Bangkok, where two of the animals were born.

"We believe they were smuggled into Thailand and put in private zoos or tourist attractions around Phuket," Tuenjai Noochdumrong, the director of Thailand's Wildlife Conservation Office.

Many private zoos in Thailand have animal shows where orangutans perform Thai kick boxing and other acts.

Thailand is trying to shed its image as a hub for black market wildlife trading and has been cracking down on violators.

Over the past 10 years, Thailand has returned 52 orangutans to Indonesia as part of a program to fight the illicit wildlife trade and send animals home to their countries of origin, Tuenjai said.

Indonesia is home to about 90 percent of the orangutans left in the wild, but half its plush rain forest been cleared in the past half-century in the rush to supply the world with timber, pulp, paper and more recently, palm oil.

As a result, most of the roughly 60,000 remaining apes live in scattered, degrading forests, putting them in frequent and often deadly conflict with humans.