The amount of methamphetamine seized by law enforcement authorities almost doubled in 2011, prosecutorial data showed Sunday, while seizures of other drugs also rose.

The statistics from the Supreme Public Prosecutor’s Office showed that the overall number of drug offenses in Korea declined 5.7 percent to 9,174 last year, remaining below the 10,000 bar for a second consecutive year. That was low enough to put Korea among “drug-free countries” internationally.

Yet the data revealed a noticeable and disturbing trend ― increased activity on the supply side of the illegal drug market.

Despite the decline in overall drug offenses, the number of arrests for production, trafficking and trade of narcotics rose 7.4 percent to 2,179.

Seizures of methamphetamine, once trademarked as Philopon, jumped 97.9 percent from 2010 to 23.5 kilograms, while marijuana rose 87.8 percent to 83.6 kilograms, the two taking up 76 percent of the total by weight.

Some 60 grams of hashish were seized, up 60.8 percent from a year ago.

The prosecution said much of the methamphetamine seized seems to have been brought into Korea by drug rings overseas ― those operating in China, Mali and Nigeria in particular.

“It appears that Korea is being increasingly used as a drop-off point by international drug rings and that more Koreans are being hired for the delivery,” it said.

In one such case last year, authorities in Busan found 2.1 kilograms of cocaine on a Panama-registered cargo ship which had arrived from the U.S. state of Georgia.

Sunday’s data also showed the number of foreign nationals nabbed for drug offenses dropped 65.6 percent to 295. They came from 27 countries. In 2010, the figure was 858 from 31 different countries.

By Lee Sun-young (milaya@heraldcorp.com)