South African customs officials have seized 267 kilogrammes of ivory worth 4 million rand (326,000 dollars) on the black market, the South African Revenue Service (SARS) said Friday. Customs officials at Johannesburg's Oliver Tambo Airport noticed a pallet containing plastic-wrapped boxes. They had been declared as handicrafts from Zimbabwe, but turned out to be elephant tusks, dpa reported. The illicit cargo was destined for Vietnam. Ivory is used in Asia in traditional medicine and for decorative purposes. The Convention on International Trade in Endangered Species (Cites) banned the ivory trade in 1989. The seizure was one of the biggest in South Africa so far.