Customs authorities of Dalian Port in northeastern China are stepping up customs inspections of shipments to North Korea.

According to sources in the region, customs of Dalian Port sent a letter to local logistics companies which act as customs procedure agencies to ask them to strictly observe clearance regulations for North Korea-bound shipments.

The Chinese port, which has been accused as a passage for illegal cargo destined for North Korea, toughened customs inspections of cargo to the North after Pyongyang launched a long-range missile at the end of last year.

The sea route connecting Dalian Port with the North’s Nampo Port is a major passage for ordinary imports and exports for the North as well as foreign aid of food and fertilizer to the North.