The authorities are stepping up measures to prevent the illegal inflow of Rohingya from neighbouring Myanmar.
Illegal entries by members of this ethnic group usually soar between November and April every year - after the monsoon period has ended.
The Rohingya - who are Muslim - have been fleeing for years from Myanmar's western Rakhine State, where they face severe repression in most facets of daily life by a government that regards them as "Bengalis" from Bangladesh.
"Security agencies have estimated that more than 10,000 Rohingya people will arrive in Thailand via Ranong and nearby provinces between next month and April next year," Deputy Ranong Governor Pinij Boonlert said yesterday.
Pinij was acting for the Ranong governor, who is the ex-officio chief of Ranong's Internal Security Operations Command, in instructing local authorities on how to address the Rohingya problem.
He said the illegal inflow of Rohingya meant Thailand would have to shoulder an extra burden.
"It is a big problem."
But he said Thai law clearly stipulates that illegal migrants must be deported. The presence of illegal migrants could threaten national security and increase other risks.
During the past few days, officials have arrested more than 200 Rohingya in southern Thailand.
An informed source claimed some illegal migrants ran into the ocean when they spotted officials and were swept away by waves and not seen again. Their fate remained unknown as of press time.
Pinij said the ISOC had laid down guidelines to handle Rohingya issues.
"We shall treat them in line with humanitarian principles, respect for their human rights and international laws. But we will have to deport them," he said.
Focus on agents
And if an illegal migrant was found to be linked to an agent smuggling people, a probe would be launched to find the agent.
"Such agents have flouted Thai laws," he said.
Pinij said the authorities believed there were many human smugglers because Rohingya were often found with mobile phones.
Relevant authorities plan to educate the public so people understand that the presence of the illegal migrants could adversely affect the country.
Pinij said a number of Rohingya used small fishing trawlers to travel some 1,400km from Myanmar's Maungdaw to Ranong. "They will usually hide on some nearby island, split into very small groups, then sneak into Thailand," he said.