Korea Customs Service officers demonstrate a baggage inspection for drug smuggling at a dedicated narcotics screening station in the arrivals hall of Terminal 1 at Incheon International Airport, Wednesday. Korea Times photo by Shim Hyun-chulKorean customs authorities seized a record 1,007 kilograms of narcotics intended for the domestic market in 767 cases during the first half of the year, the Korea Customs Service (KCS) said Wednesday.The haul was equivalent to about 33.58 million doses, based on a 0.03-gram dose. While the number of cases rose 24 percent from a year earlier, the total weight fell 62 percent because last year's figures included drugs merely transiting through Korea. Excluding those transit shipments, this year's haul was the largest on record for drugs destined for the domestic market.KCS Commissioner Lee Jong-wook said during a media briefing that the increase was driven by traveler smuggling, vowing to step up inspections of arriving passengers by expanding a multilayer screening system, including random inspections immediately after arrival and X-ray screening of all checked baggage.The number of traveler smuggling cases jumped 79 percent, while the amount seized rose 23 percent from a year earlier.By contrast, seizures through international mail dropped sharply after customs strengthened secondary inspections at five international mail centers late last year, prompting traffickers to shift to passenger routes, the KCS said.Korea Customs Service officers demonstrate the use of a millimeter-wave body scanner to detect drug smuggling at a dedicated narcotics screening station in the arrivals hall of Terminal 1 at Incheon International Airport, Wednesday. Korea Times photo by Shim Hyun-chul Marijuana accounted for the largest share of drugs seized, followed by methamphetamine, ketamine and cocaine.Thailand was the largest source country, followed by the U.K., Canada and Vietnam.People in their 30s or younger accounted for 59.3 percent of all drug-smuggling suspects in the first half, with teenagers making up 2 percent, underscoring the spread of drug-related crime among younger people.In addition to strengthening inspections of arriving passengers, Lee said the agency plans to expand its multilayer inspection system to cover express cargo, vessels, crew members and port workers while deploying additional detection equipment such as ion scanners, Raman spectrometers and millimeter-wave body scanners."Drug smuggling remains the KCS' top enforcement priority because narcotics pose a serious threat to public health and public safety," Lee said, urging travelers not to carry luggage or packages for acquaintances or strangers while abroad because they could unknowingly become involved in drug trafficking.