The military task force responsible for tackling human trafficking says it is stepping up measures to thwart trafficking of Rohingya migrants from Myanmar to Malaysia via Thailand.
It is currently the peak season for trafficking activities.
Trafficking networks are usually most active between November and May while the seas are calm, making it easier to transport migrants by boat, said Col Kriangkrai Srirak, chief of a special unit attached to Thep Satree Task Force.
The military has been stepping up inspections of boats to prevent trawlers which have smuggled Rohingya from Rakhine state in Myanmar from stopping to unload the illegal migrants in southern Thailand, he said.
In many cases, fishing trawlers have been modified to accommodate up to 500 migrants.
They usually dock in Ranong where they enter Thailand illegally and begin the last leg of their journey to Malaysia, Col Kriangkrai said.
Currently about 400 Royingya are detained both in Muang districts of Ranong and Surat Thani, where they are under the care of the Social Development and Human Security Ministry.
These illegal migrants will be treated as witnesses in human trafficking cases because they are considered victims of trafficking gangs, he said.
Aside from testifying as witnesses, the detained migrants will have to undergo nationality verification so they can be deported back to their country of origin.
Setting up a formal shelter for Rohingya is not an option because it is against the wishes of local people and the government's security policy, he said.
A public opinion survey conducted by the army in Ranong recently showed locals there did not agree with the shelter idea.
It normally takes about 15 days for trawlers to travel from Rakhine to southern Thailand.
Traffickers typically charge migrants between 40,000 baht and 60,000 baht for the service, Col Kriangkrai said.
Security checkpoints are now set up at sea to search suspected boats before they enter Thai waters. Marine patrols are also being conducted regularly, he said.
Col Kriangkrai said the standard approach in dealing with trawlers carrying illegal migrants is to intercept them, provide those on board with food, drinking water, medicine, fuel and then tow them back out to sea.
Tow-backs are part of defence policy, he said.
"Of course we feel sorry for them, especially when there are women and children on board. But as soldiers it is our duty to follow policy and push them back out."