Police in Thailand’s southern Songkhla province on Wednesday arrested 46 illegal Burmese migrants after raiding the offices of a company run by a Burmese Muslim.

The raid was ordered as part of heightened security measures in Thailand’s restive southern provinces, a border patrol police officer told The Irrawaddy. Hat Yai immigration police carried out the raid on Tuesday night, on the Hat Yai offices of a company called Inter Toptour Co Ltd, and recovered visas and other documents. The company is run by a Burmese businessman, Than Tun, also known as “Sunny.”

On Wednesday, immigration police arrested 46 illegal Burmese migrant workers in a Hat Yai camp. They are to be repatriated to Burma, and inquiries are to be made about their possible involvement in separatist activities in southern Thailand, the police said. Than Tun’s suspected role in bringing them to Thailand is also to be investigated.

Earlier this month, another Burmese citizen, Abi Raman, also known as “Bailey,” was arrested on suspicion of running an agency for illegal Burmese migrants. Police say he is also being investigated for possible involvement in the bombing of a department store in Hat Yai in April.