China has reportedly enhanced efforts to block North Korean exports of weapons and nuclear materials.

Chinese sources on North Korea and businessmen trading with the North in China said that in May, following the North's nuclear test, Chinese authorities installed up-to-date automated radioactivity detecting facilities at customs outposts near the border area with the North.

Due to enhanced inspections, the sources say numerous shipments of North Korean mineral products have been rejected.

The U.N. Security Council is nearing the adoption of a set of sanctions on the transport of weapons of mass destruction or related materials in and out of the North.