The broadcasting of nine stations had affected flight control communications, while programmes broadcast on 14 frequencies generated from another nine stations failed to comply with regulations, which limit advertising time and encourage promotion of "local wisdom", he said.

Of 66 applications submitted this year for operating licences, Worrachai said most failed to follow basic technical requirements regarding broadcasting: the wattage output must not exceed 30 watts, the height of antenna towers must not exceed 30 metres and the reception radius must be limited to 15 kilometres.

He said there were are only a few radio stations that properly serve the community, while most were used for commercial purposes. A 48-member committee has been set up to verify applications to sort out those submitted by people who are not really interested in promoting local wisdom.