Från Wikipedia-artikeln för filmen ...
Co-writer Drew Dowdle says, "'We worked very closely with the Thai government and there were a lot of things they wanted us to shy away from ... So although the film shows a coup breaking out in a Southeast Asian city, ... it never specified the country. We were very careful not to make it Thailand in the movie, so there was no Thai language used'", said Drew. "'None of the signage is Thai and most of the language that the native population is speaking is a combination of Laotian, hill-tribe languages and other languages,'" however they are actually speaking Khmer, native Cambodian.