More than 6,000 exotic animals including monitor lizards and mud turtles believed to be bound for Hong Kong have been intercepted on Malaysia's east coast, police said on Friday.

Marine police who mounted a raid on a jetty on Thursday detained six men including five Hong Kong nationals, regional commander Mohamed Salleh Mat Ghani told the state Bernama news agency.

"On arrival at the scene, the raiding party found some 30 people transferring wooden boxes from a boat to two trailers. However, all of them fled after realising the presence of the police," he said.

The Hong Kong nationals were nabbed on the boat, he said, adding that they did not have any valid travel documents and would be handed over to the Immigration Department.

Pahang state's Wildlife and National Parks director Zainuddin Abdul Shukor said the seized animals were protected species.

He said the department would release them back to their natural habitat at various sanctuaries and national parks.

The marine police did not say what the animals were wanted for, but most smuggled wildlife in Asia is destined to be killed and served in restaurants, while some are highly prized as ingredients in traditional Chinese medicines.