WUHAN - A drug gang posing as household decorators have been caught manufacturing drugs in apartments in Central China's Hubei province.

Police with the public security bureau of Wuhan, Hubei's capital, raided three workshops manufacturing drugs in late August, seizing 13 suspects, according to a statement released by local police Monday.

The police confiscated more than 20 kilograms of yaba (a stimulant composed of methamphetamine and caffeine), 20 kilograms of drug materials, drug-making equipment, two hand grenades, four pistols and several imitation pistols and bullets.

As the drug-making equipment, weighing around one tonne, was very noisy, the gang usually hid the machine in new neighborhoods that had many decoration teams. They also set up a shock-absorption device on the bottom of the machine.

A resident in the neighborhood told police that he heard loud noises inside the apartment but thought it was people decorating.

Each gang member had a specific role. Younger members learned how to make drugs online, while older members sold the drugs and provided financial support for the gang.

In order to produce quality drugs, they even recruited two experts from southwest China's Yunnan Province who had learned to make drugs overseas.

Currently, eight members of the gang have been detained by police for manufacturing and selling drugs.

An investigation is ongoing.