Figures released by local customs authorities Thursday strengthened our perception that Korea can no longer be perceived as a place relatively free of narcotics. The number of drug-smuggling cases uncovered by the Korea Customs Service increased from 150 in 2009 to 232 in 2012 and further to 308 last year.

The amount of banned substances confiscated last year totaled 71.7 kg with a street price of 150 billion won ($137 million), up 54 percent and 62 percent, respectively, from the previous year. Methamphetamine, more commonly known as philopon here, took up the largest portion with 50.8 kg, the biggest amount impounded by the KCS since 2004.

The sharp rise in drug smuggling into the country seems mainly related to international crime rings increasing trafficking from their manufacturing bases in other Asian nations. More than 90 percent of the methamphetamine confiscated at local airports and harbors last year was linked to crime organizations, according to KCS officials.

The crackdown on narcotics smuggling should continue to be strengthened to prevent the spread of illegal drug use in the country.

It is also worrisome that Korea is increasingly being used as a transit point for international drug trafficking. KCS data show the amount of methamphetamine seized here on its way to a third country has increased continuously in recent years.

International drug-trafficking rings seem to regard Korea as part of a useful route to deliver narcotics produced in China and some Southeast Asian countries to the U.S., Japan and Europe. Many ordinary Koreans have also been cajoled or trapped by them into transporting drugs, often being subject to grave punishment in countries where they were captured. The misuse of Korea’s reputation as a place relatively immune from narcotics is reaching the point that tougher and more effective measures should be implemented urgently to block the practice.

The customs authorities should install more advanced detectors at airports and harbors in the country and operate a unit tasked with collecting and analyzing information on drug smuggling. They need to further strengthen cooperation with the prosecution, police and other law enforcement agencies at home and abroad to crack down on drug traffickers more effectively. It is also necessary for the KCS to join an arrangement set up by the World Customs Organization to prevent the spread of narcotics.

Efforts should also be strengthened to block attempts by individuals to bring in small amounts of illegal stimulants hidden in other items through international mail or other courier services. KCS data showed 228 packages hiding drugs were confiscated last year, up from 139 packages in the previous year. Of particular concern was that the number of teenagers caught trying to buy illegal drugs from foreign Internet sites increased to 10 in 2014 from one in 2013. More serious dialogue is needed to work out ways to keep youths from obtaining psychoactive substances in cyberspace.