Sources say the move follows an order to block foreign influences.
The FBI cites ‘significant overlap’ with other attacks engineered by the reclusive nation.
North Koreans are buying solar power systems from a Chinese border town for home installation.
He had applied for asylum in Denmark after escaping a political prison camp.
Sources say authorities want to root out illicit cell phones.
The move appears aimed at boosting domestic production in the cash-strapped country.