From Reuters:

China has reduced rail freight traffic to North Korea in recent weeks, holding up some shipments of humanitarian aid to the impoverished country, an aid agency and rail authorities said on Friday.

The move was apparently taken in anger over Chinese rail cars going missing in North Korea, where analysts say they are sometimes disassembled and sold as scrap metal.

“A lot of Chinese rail cars have piled up in North Korea and have not come back,” said an official in the cargo division of China’s Railways Bureau in Dandong, the Chinese border city through which most freight to North Korea passes. [Full Text]

Read also Food aid to North Korea being held up in China over rail dispute by AP.