Police in Huizhou, Guangdong province, announced on Thursday that 38 suspects of a drug gang have been arrested.

Police seized 15 kg of ketamine. The gang is said to have two drugmaking sites in Heyuan and Jiangxi province's Ganzhou. The drugs are said to have been sold in Huizhou, to Dongguan and to Taiwan.

According to police, one of the suspects is a man from Taiwan who works in Dongguan. He is believed to have bought 238 kg of drugs worth 3.3 million yuan ($539,600).

Another gang was cracked in two simultaneous raids by police in Huizhou and Heyuan in Guangdong and Yancheng in Jiangsu province on July 6.

Police arrested 28 suspects, seized 181 kg of ketamine and 1.8 million yuan in cash. The suspects belong to a huge gang of drug makers and dealers, and has sources in Jiangsu offering raw materials, a factory making drugs in Heyuan and a sales network covering seven cities in Guangdong including Huizhou, Foshan, Dongguan and Meizhou.

"It's a big success for us to track down the sources of raw materials. Among the drug crimes we have cracked down, only in a few cases we are able to smash up the whole criminal network," said a police officer surnamed Liu from the public security bureau of Huicheng district in Huizhou.

Both gangs set up their drug making sites on a remote mountain. The first gang's site, located in Heyuan, was disguised as a pig farm.

"Many drug making sites used to be hidden in abandoned houses in rural areas, and now they are moving to more convert locations such as steep mountains," said an officer surnamed Li from the anti-drug brigade of Huizhou Public Security Bureau.