THE BURNED OVER DISTRICT

So they have put foreign residents on notice that they should not bring porn or other subversive materiel into the country and never share it with Best Koreans.

North Korea has warned foreigners living in Pyongyang not to share outside media on memory sticks with its citizens, the Ministry of Foreign Affairs said in a note, cracking down on what the isolated country called "undesirable content".

The vast majority of North Koreans have no access to outside Internet or foreign media, but people regularly share films, music and literature on easily-concealed USB sticks that are passed from person to person.

The note, a copy of which was seen by Reuters, said foreigners in Pyongyang would not be allowed to import "all kinds of data media, including printed matter, mobile phones, and memory sticks" which contain "false propaganda" and "photos, movies, and literature regarding sexual relations".

Some foreigners entering the country had left printed materials and memory sticks containing "undesirable content" at tourist sites, or passed them to North Koreans, the note added.

"We regard these practices as a serious problem directly related to the security of the State," said the note, which was dated Thursday and addressed to diplomatic and international missions in Pyongyang.

"Accordingly concerned authorities of the DPRK are taking such measures as strict censorship over printed matters and memory media at every port of entry to the DPRK, including the airport."

DPRK is short for the Democratic People's Republic of Korea, North Korea's official title.

The note warned that although those holding diplomatic passports were exempt from direct censorship, anyone found with offending material "must bear all the blame to themselves, entailing appropriate measures here".

Embassies in Pyongyang were looking into whether the note infringed the Vienna Convention on Diplomatic Relations, a diplomatic source in Pyongyang told Reuters. The 1961 convention forms the basis of diplomatic immunity.

Who would want to be a diplomat in Best Korea if they couldn't bring their own porn?