The North Korean government has ordered the destruction of 10,000 homes on the most porous stretch of its border with China in an effort to clamp down on defectors and smugglers.
Residents of homes between the cities of Hyesan and Musan, 85 miles to the north-east, have been forcibly removed and resettled in communities further back from the rivers that form the frontier, according to South Korea's Chosun Ilbo newspaper.
Quoting an unidentified source, the report said a major new road has been built on the North Korean side of the border, while the people whose homes were destroyed were encouraged to leave with the promise of extra food.
With the nation stricken by a drought, aid agencies have warned that North Korea's harvest is likely to be significantly short of the amount that is needed to feed the nation's 23 million people, and the additional supplies that were promised have not been provided, the source claimed.
Defectors condemn North Korea peace march
The reports tally with claims by defectors that North Korea has dramatically stepped up security on its border with China.
"The situation on the border is not safe and arranged defections out of North Korea are more expensive and less frequent as a result," an activist assisting defectors in China told The Telegraph.
Escape from North Korea: 'How I escaped horrors of life under Kim Jong-il'
Patrols have similarly been stepped up on the Chinese side of the frontier, in part because of an increase in violent incidents apparently involving desperate North Koreans targeting Chinese civilians.
Chinese police are also attempting to dissuade anyone from helping North Korean defectors once they get over the border and are questioning anyone who is not a local resident or who does not have the correct papers, activists reported.
By Julian Ryall / The Telegraph