Bangladesh's coast guard rescued 33 refugees and detained six alleged human traffickers from a fishing trawler headed for Malaysia in the Bay of Bengal, an official said Wednesday.

The rescued included 14 men, 10 women and nine children who had been living in refugee camps in the southeastern Bangladesh district of Cox's Bazar, according to Fayezul Islam Mondol, coast guard commander in the southeastern coastal town of Teknaf.

"We have captured six traffickers as well. All of them are Bangladeshis," he told AFP.

Some 720,000 refugees of a Myanmar minority have taken shelter in Bangladesh camps since August last year.

People smugglers in recent years have sent tens of thousands of refugees from the Bangladesh camps to Malaysia, before Bangladesh launched a crackdown in 2015 after Thai authorities discovered mass graves and boats overcrowded with thousands of migrants drifted at sea.

Mondol said the Rohingya rescued Wednesday had boarded a dilapidated fishing trawler on an uncertain "sea voyage to Malaysia".

The boat was intercepted Wednesday evening by a coast guard boat near Saint Martin's Island, the last territory of Bangladesh, situated only a few kilometres (miles) away from Myanmar's Anauk Myinhlut coastline.

One of the arrested traffickers, Abdus Shukur, 55, told AFP that the fishing trawler had been due to transfer the Rohingya to a bigger Malaysia-bound ship moored near the island in the Bay of Bengal.

"We were forced by an influential local to take these (Rohingya) people on the fishing boat. We were instructed to board them on an awaiting ship near Saint Martin's," Shukur said.

Authorities in Bangladesh worry many refugees may once again risk travelling to South-East Asia by boat, a route previously popular among Rohingya seeking economic opportunities outside the grim and crowded camps.

Most voyages take place between November and March when seas are most calm.

A local government official said with the approach of winter, traffickers were now trying to lure Rohingya again to the dangerous boat journeys.

"The sea is getting calm and there is high demand among the refugees to travel to Malaysia," Teknaf mayor Abdullah Monir said.

"The traffickers are therefore taking the opportunity to float their boats again," he said.

On Tuesday, Border Guard Bangladesh (BGB) detained 14 Rohingya on Teknaf coast who had allegedly been cheated by human traffickers.

Local BGB spokesman Major Shariful Islam said they paid nearly $120 each to a fellow refugee in Kutupalong, the largest Rohingya refugee settlement, to be sent to Malaysia.

"But the man sent them to a brief boat journey and later dropped them off the Teknaf coast after three days," Islam said.

© AFP