Three Thai villagers suspected of spying on Thai soldiers and passing information to Cambodian forces were arrested on Thursday for interrogation, 2nd Army spokesman Col Prawit Hukaew said.
The three were apprehended near Ban Don Nam Tan in tambon Bak Dai of Surin's Phanom Dong Rak district.
They are suspected of reporting the locations of targets by mobile phone to Cambodian soldiers for attack.
They were identified as Thanit Srisa-nga, of tambon Khok Klang, Sanit Pinkao, of Ban Nong Khanna, and Sermsuk Phochaiserm, of Ban Don Nam Tan.
Col Prawit said the three were still being questioned and it was not yet confirmed they were spying for Cambodia.