HAIKOU, June 26 (Xinhua) -- China executed four drug traffickers Friday, which was the annual international anti-drug day, in the southern island province of Hainan.

    The four Chinese men, identified as Zheng Jinhai, Zeng Yina, LiAnyue and Liu Dacheng, had been sentenced to death for selling drugs, according to the Intermediate People's Court of Haikou, the provincial capital of Hainan.

    They were involved in three cases involving a total of 8.695 kilograms of drugs, the court said.

    On Thursday, eight people who had been sentenced to death for drug production and trafficking were executed.

    The death penalty is usually imposed by local courts and subject to review and approval by the Supreme People's Court.

    Also Thursday, the Liaoning Provincial Higher People's Court in northeast China announced that two men convicted of heading a gang that smuggled drugs from Myanmar into China were executed in May.

    Zhang Jun, vice president of the Supreme People's Court, told reporters Thursday that China was still facing 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 said.