Thai police said Wednesday they had seized 16 elephants from tourist destinations as part of a nationwide swoop on operators suspected of using smuggled wild pachyderms for entertainment.

The animals were removed on Tuesday and Wednesday from camps in the southern and eastern resort areas of Ko Chang, Phuket, Krabi and Phang Nga, which are popular with holidaymakers, said Police Colonel Watcharin Phoosit, from the Natural Resources and Environmental Crime Suppression Division.

A further planned raid on Friday is expected to seize 10 more elephants from Kanchanaburi in the west, central Chonburi and the northeastern provinces of Surin and Chaiyaphum.

"If the mission is successfully completed on Friday, it will be the biggest seizure we have ever had -- 26 elephants in total," Watcharin told AFP.

Camps and zoos featuring elephants tightrope-walking, playing football or performing in painting contests employ almost 4,000 domesticated elephants for the amusement of tourists in Thailand.

But the capture of wild elephants for entertainment use is banned. Last year Thai authorities conducted several raids on elephant camps and seized some 25 animals.

Wildlife group Traffic, which monitors the trade in animals, said the recent raids were conducted after police found dozens of suspect elephant identification certificates.

"Police believe that elephants were taken from the wild, either in Myanmar or elsewhere, smuggled into Thailand where they were trained, transferred to the camps, and then registered at a later date using these falsely provided certificates," the group said in a statement.

Domestic elephants in Thailand -- where the pachyderm is a national symbol -- have been used en masse in the tourist trade since they found themselves unemployed in 1989 when logging was banned.

Just 2,000 of the animals remain in the wild.

Thailand is a signatory to the Convention on International Trade in Endangered Species, which bans the cross-border trade in elephants, Traffic said.

It welcomed the "significant" swoop but urged the country to tighten its regulations which currently do not require proof that an animal was born in captivity.

"The system thus opens the door to the laundering of elephant calves, with criminals catching these calves from the wild, smuggling them into the country and registering them as domesticated elephants," the statement said.

Watcharin said camps "usually take elephants when they are babies because tourists like them, they are small, easy to be trained and don't eat much."