SHENYANG, China -- China has strengthened its smuggling crackdowns in areas bordering North Korea in response to its wayward ally's latest ballistic missile and nuclear tests, sources said Monday.

According to the sources, China made customs clearance procedures for trade with the North harder in the wake of the North's Hwasong-14 ballistic missile launches on July 4 and 28, and is intensively cracking down even on small-scale contraband trade between the two countries after Pyongyang carried out its sixth nuclear test on Sept. 3. 

In particular, trade vehicles from the northeastern Chinese cities of Dandong, Liaoning Province, and Longjing, Yanbian Korean Autonomous Prefecture, are now under strict customs inspections, the sources said.

In addition, barricades made of sandbags have been set up on rural roads leading to the Amrok and Tumen Rivers dividing North Korea and China in order to control vehicles, as they are main routes for bilateral smuggling, the sources said.

China has suspended imports of coal, minerals and fishery products from the North since Aug. 15 as part of measures to implement Resolution 2371 sanctions against the North's missile tests. (Yonhap)