Eleven people have been arrested after police in Guangdong made their biggest sei zure of heroin this year, it was reported yesterday. Xinhua said officers in Jieyang seized 166kg of the drug. It came after a four- month investigation following a tip-off in March. Police arrested 33-year-old Wu Zaiwu who was described as the gang's leader. Wu, who lived in Puning city, was said to have masterminded a major syndicate smuggling heroin from Yunnan province to Guangdong. Officers made their first arrests early last month when they rounded up four members of the gang and found 14kg of the drug. They discovered another 152kg of heroin when they swooped on Wu on July 29 and searched two vans. The heroin was said to have been hidden in secret compartments under the driver's seat.