Nearly 18kg of high-grade heroin, with a street value of HK$10.6 million, has been seized at Chek Lap Kok airport and eight people charged with drug trafficking in the past few weeks. The eight suspects include two Filipino women and six African men. Customs officers believe at least two international drug-trafficking syndicates are behind the haul. Two Filipino women were found carrying 3.1kg and 5.5kg of heroin hidden in their luggage. They were stopped in separate cases on March 26 and 30. The six Africans were found to have swallowed 9kg of heroin in pellets and were stopped between April 16 and Tuesday. The suspects, aged between 24 and 35, had travelled from Dubai, India, the Philippines and Malaysia when they were stopped entering Hong Kong, said Ben Leung Lun-cheung, head of the Customs Drug Investigation Bureau. 'The drugs were smuggled into Hong Kong via different routes. [The suspects] used different methods to conceal the drugs to avoid them being detected,' Mr Leung said. He said the drugs, which had come from the drug-producing area across Afghanistan, Iran and Pakistan known as the Golden Crescent, had been destined for the mainland. 'The smugglers might have thought our frontline officers have become less alert after two successful operations. 'So they tried to smuggle the drugs into Hong Kong through our busy checkpoints at the airport,' said Mr Leung, referring to the arrest of 14 Thais between March and May last year for carrying 9kg of heroin between them, and the seizure of 30kg of heroin in November 2006. He said customs officers were always on the alert at the city's checkpoints and that officers worked closely with mainland and overseas authorities to clamp down on drug offences.