Immigration authorities have identified suspects involved in the smuggling of more than 200 illegal Muslim immigrants detained in Songkhla, a senior police officer says.
Immigration Bureau chief Panu Kerdlarppol said the authorities homed in on the individuals after investigating the vehicles used to transport the migrants.
According to Lt Gen Panu, Thai authorities have yet to identify where the migrants are from. They were arrested at a rubber plantation in Songkhla on March 12 claiming to have arrived via Turkey.
However, they are suspected of being ethnic Uighurs from China's northwestern Xinjiang region.
Pol Gen Panu said authorities believe the migrants and another group of 112 Muslim migrants held in Bangkok's Suan Phlu immigration office belong to the same group.
He said of the 112 migrants, Chinese authorities have helped identify 30 of them as ethnic Uighurs. The nationality of the others is being verified.
According to the immigration chief, the migrants are suspected to have entered the country via either Myanmar, Laos or Cambodia.
The 112 migrants were rounded up from Sa Kaeo after entering Thailand through northern border provinces.
After an inspection of the Thai-Malaysian checkpoint in Songkhla's Sadao district, Pol Lt Gen Panu said Songkhla intends to expand the immigration office's holding facility to accommodate the increase in the number of Rohingya migrants arrested recently.
To make sure the facility will not turn into a refugee camp, it will be used to detain male immigrants only, he said, adding that women and children will be sent to another facility.
Construction plans for the holding facility are being discussed with the United Nations High Commissioner for Refugees, he said.
"Immigration detention centres are used to hold immigrants for a week or two. Long stays by Rohinya immigrants are problematic as they have tried to escape several times," he said.
Meanwhile, a total of 115 illegal immigrants were arrested in two separate cases yesterday in Phatthalung and Songkhla, police said.