The southern coastal city bordering Hong Kong will increase its efforts to combat the smuggling of refined oil and the activities of petty smugglers, Shenzhen customs said on Friday.

On Friday, Wang Zhi, deputy chief of Shenzhen customs, reported on the department's anti-smuggling work in the first quarter. So far this year, the department has handled 46 criminal cases with a total value of more than 71 million yuan ($11 million). Customs officers have seized more than 3,000 grams of heroin, 343 tons of refined oil, 1,354 kilograms of silver and a large number of iPhones and other electronic devices.

Wang said that despite those seizures, customs officers still face severe challenges. The smugglers have developed a wide variety of methods and are becoming increasingly intelligent and professional. Petty smugglers remain a major problem despite a crackdown on their activities. Meanwhile, the smuggling of popular electronic products is increasing, while drugs and weapons trafficking remain active.

According to Wang, the smuggling of refined oil is rampant as gasoline prices on the mainland continue to rise, providing easy profits for those smuggling the fuel from Hong Kong.

On March 14, Wang said Shenzhen customs seized a diesel-smuggling gang and confiscated 15 tons of smuggled fuel. To carry out their illegal trade, the gang used vans bearing Hong Kong-Guangdong license plates, which allow unhindered access between Hong Kong and the mainland.

The smuggling of electronic products, including iPhones and iPads, has been highly active. On March 13, a Shenzhen middle school student was seized at Shatoujiao Port by the customs. She had secured 25 iPhone 4s, worth more than 80,000 yuan, around her waist and legs. She had been promised just 200 yuan for the trip.

According to the city customs office, the petty smugglers are mostly residents of Hong Kong or people holding Shenzhen hukou (permanent residency permits) who travel between Hong Kong and the mainland several times a day. They use a variety of smuggling methods: apart from the traditional method of tieing the goods around their bodies, or hiding them in their clothes and luggage, smugglers also stow contraband in their shoes, in baby strollers, paper diapers, tins of milk powder, and in school bags. The gangs also use express mail and through freight to transport the goods.

On March 21 at Huanggang Port, customs officers seized a van that had 100 iPod Touch devices hidden in a small space the driver had created inside the vehicle.

"In the past, petty smugglers were mostly low-income Hong Kong residents, but now transport in and out of (Hong Kong) has become more convenient, especially since 2009. Residents with Shenzhen hukou can enter Hong Kong a limitless number of times every year. We've see a large increase in the number of Shenzhen residents among the petty smugglers," said Wang.

He added that Shenzhen customs will cooperate with Hong Kong's transportation authorities to restrict the flow of oil to smugglers, and to investigate their sales network. To deal with petty smugglers, the customs department is considering setting up a separate lane at its ports for those suspected of smuggling and who travel between Hong Kong and the mainland several times a day.

huangyuli@chinadaily.com.cn