Custom officers at an Indian airport have found more than 10,000 live turtles in suitcases and arrested the two passengers suspected of trying to smuggle the reptiles from China to Singapore.

Authorities at the Netaji Subhas Chandra Bose International airport in the eastern city of Kolkata said the two detained on Thursday were Indian nationals.

"10,043 numbers of exotic varieties of the turtles have been seized from two passengers, residents of Chennai, who were coming from China to Singapore, and landed at Kolkata airport," said assistant commissioner of Airport Customs, Nabnit Kumar.

Nearly all species of sea turtle are classified as endangered, according to World Wildlife Fund (WWF).

Human activities have imposed a threat of extinction on several species of turtles. Increasing pollution, drainage of wetlands and commercial development tend to destroy the habitats and nesting sites of turtles.

WWF says that turtles suffer from poaching, are slaughtered for their eggs, meat, skin and shells, and fall prey to over-exploitation.

Officials said an investigation had been launched into the attempted smuggling case.