By The Nation
Pol Lt Gen Sompong Chingduang cited official records and recordings from security cameras at a border checkpoint in Narathiwat, which clearly showed their faces.
The men were arrested in Chumphon early on Friday after allegedly planting two homemade bombs in front of Royal Thai Police headquarters the day before.
The bombs were found and defused before they could detonate.
Sompong declined to disclose the dates on which the pair entered Malaysia or who might have been in their company.
These details had been passed on to Police Commissioner Pol General Chakthip Chaijinda, who might make them public later, he said.
Sompong said Chakthip had instructed immigration officials at all border passes, airports and seaports to carefully check everyone crossing.
Those in the southern border provinces were instructed to pay particular attention to vehicles.