ANTI-DRUGS officers swooped on a Wan Chai disco early yesterday, the third raid in eight days to target increasingly popular 'rave' drugs. Five people were arrested and more than 100 Ecstasy tablets seized in the operation, which comes a week after an official survey found the number of young drug abusers had soared 40 per cent in the past year. Police also found 3.5 grams of heroin, 15 grams of ketamine and 10 rolls of cannabis when they raided the Gloucester Road disco at about 1.30am. Two men and a woman were arrested at the scene, and two other men were apprehended later in Yau Ma Tei and Tsim Sha Tsui. The suspects are aged 20 to 26 and were being questioned by police yesterday. Last Saturday, 21 people were arrested in raids on a rave party in Sha Tin and several bars in Wan Chai. More than 100 officers interrupted a party at the Regal Riverside Hotel and made nine arrests for ketamine possession and identity card offences. In Wan Chai, seven men and five women were escorted from five bars and clubs. They were held on suspicion of possessing ketamine, trafficking in dangerous drugs or failing to produce ID cards. The day before, five men and two women were arrested at a flat in Argyle Street, Ho Man Tin, after police seized 400 Ecstasy tablets and other rave drugs worth $65,000. The haul included 'ice', cannabis and ketamine. That raid came a day after Narcotics Commissioner Clarie Lo Ku Ka-lee said an increasing number of young people were taking psychotropic drugs such as Ecstasy and ketamine as the 'rave' culture became more popular. The number of drug users under 21 rose 38 per cent in the first quarter of this year compared to the last three months of 1999, while the number of people using Ecstasy had doubled in proportion to other drugs. Ketamine is a painkiller for animals that produces hallucinations in humans.