South Korea on Tuesday conducted a crackdown on smuggled North Korean products coming in from third countries in a move to faithfully enforce United Nations sanctions and its unilateral punitive actions, government officials said.

Seoul's unification ministry and eight government agencies carried out a joint surveillance on North Korean products which are suspected of entering South Korea disguised as goods manufactured in other countries, they said.

The ministry said that officials inspected three marketplaces in the capital city to check for smuggled North Korean products and to advise merchants not to sell them if they were found.

The United Nations Security Council slapped North Korea with the toughest sanctions to date in March over Pyongyang's nuclear test and long-range rocket launch conducted earlier in the year. The UNSC is working on a fresh sanctions resolution for the communist regime's fifth nuclear test in September.

On March 8, South Korea announced its own unilateral sanctions, including a ban on the entry of vessels into South Korean waters that have sailed to North Korea in the past 180 days, and tighter control on North Korean product imports.

The government said that since March, there has been a sharp decline in North Korean products being sold in the South.

In the January-August period, authorities detected 16 cases of smuggled North Korean goods worth some 300 million won ($264,780), down from 23 cases valued at 3.3 billion won for the whole year of 2015, the ministry said. (Yonhap)