The extension of the wall that is now separating Songkhla's Sadao district from Malaysia's Padang Besar will help help prevent an influx of illegal workers into Thailand.

"The wall will help authorities check and prevent illegal immigrants from coming in and out of Thailand," Surayud told reporters. He was visiting the restive south.

Now Thailand already has a three kilometre (two mile) wall on its southern border.

Surayud said the government would extend the existing wall south by 27 kilometres to Yala.