China has placed some 10,000 of its troops near its border with North Korea in an apparent attempt to stop an influx of North Korean refugees trying to flee their homeland.

Japan’s Sankei Shimbun quoted sources in China as saying the troops were positioned there not long after rumors that groups of North Korean soldiers patrolling the border may attempt to defect themselves.

The paper said Beijing was concerned about the possibility of armed soldiers seeking refuge in China’s provincial cities.