BEIJING, June 25 (Xinhua) -- Eight people who had been sentenced to death for drug production and trafficking were executed Thursday in China amid intensified crackdowns ahead of the annual international anti-drug day, which falls on Friday.

    The Supreme People's Court said six Chinese nationals, five men and one woman, were executed Thursday morning. They were involved in four cases of drug production, trafficking or selling.

    The court did not disclose the locations of these executions. The death penalty is usually imposed by local courts and subject to review and approval by the Supreme People's Court.

    The six were Wang Xilin, Lu Gang, Zhou Zhenjun, Wang Li, Li Ersa and Yan Chaomin, the court said at a press conference. In their cases, more than 400 kilograms of various drugs, including heroin and methamphetamine, were manufactured, trafficked or sold.

    Also Thursday, trafficker Tian Yulai was executed in Lanzhou, capital of northwest China's Gansu Province. In Quanzhou City, in east China's Fujian Province, Liu Huiyang was executed. He was convicted of manufacturing narcotics in 2005.

    In addition to the eight cases above, the Liaoning Provincial Supreme People's Court in northeast China said Thursday that two men convicted of heading a gang that smuggled drugs from Myanmar into China were executed in May.

    Liu Fuying and Sun Yulong were convicted last August by the court for transporting 8 kg of heroin in their bodies on trips from Myanmar to Liaoning from 2002. Another member of their gang, Liu Yuwen, was given the death penalty with a two-year suspension.

    The death penalties imposed on the eve of the annual International Day Against Drug Abuse and Illicit Trafficking was an apparent move by China to demonstrate its determination to crack down on drug-related crimes.

    Zhang Jun, vice president of the Supreme People's Court, said China still faced a grave challenge in anti-drug campaigns because of the worsening situation globally.

    Courts across China handled 14,282 drug-related cases between January and May, up 12 percent over the same period last year. In these cases, 6,379 people were convicted and received severe penalties, ranging from five years' imprisonment to capital punishment, Zhang told the reporters.

    He said judicial authorities would continue to give tough sentences to those convicted of drug crimes, particularly leaders of drug smuggling rings, repeat offenders, armed and violent drug dealers, or members of transnational crime groups.

    "The Supreme People's Court will approve drug-related death penalties without hesitation if they are sentenced by local courts in line with the right criteria," he said.

    In general, China's highest court has become increasingly cautious in upholding death sentences from lower courts in order to ensure fair trials.

    But Zhang said the nation needed to take strict measures to keep drug traffickers at bay, as drug crimes had become more rampant and sophisticated in the past two years.

    "Many unconventional methods are used in drug trafficking, such as hiding narcotics inside the human body or international parcels. Many new types of drugs have also emerged. All this makes anti-drug struggles more challenging," Zhang said.

    Heroin accounted for 75.42 percent of all seized narcotics in China in 2007, while methamphetamine, commonly known as "Ice", accounted for 12.55 percent. The proportions shifted to 65.88 percent and 20.44 percent in 2008.

    New drugs made from easily-obtained chemicals would make the situation more difficult and require constant crackdowns, Zhang said.

    "We have seen rising numbers of people in drug trafficking gangs in recent years. Their activities tend to be more and more professional," said Wu Yanjun, an official with the Liaoning Provincial Supreme People's Court.

    Courts in the province handled 1,054 drug cases from June last year to May, involving 1,797 people. The number of cases was 60 percent more than the previous comparable period, and the number of people involved was up 90 percent, Wu said.

    Statistics from Chinese customs also indicated a rise of drug trafficking cases this year.

    Customs discovered 198 cases so far this year, up 15.9 percent from a year earlier, with 278 suspected traffickers. In these cases, 430 kg of drugs were seized.

    Police authorities in Beijing said Thursday that the amount of seized drugs in the January-May period reached 211.5 kg, three times the figure in the same period last year.

    Beijing police have intensified checks on international air travelers and cargo because these were increasingly used as trafficking channels, said Xie Yongzhi, an anti-drug officer with the Beijing Municipal Bureau of Public Security.

    Police departments in other big cities including Guangzhou and Shanghai also reported a rise of drug cases this year.