Zambian anti-drug authorities have arrested 12 Chinese construction workers for allegedly cultivating cannabis without a permit, a top government official said Thursday. The group was based in the city of Chipata in Zambia’s Eastern Province where they were building a studio for the state-run Zambia National Broadcasting Corporation.

“It’s really regrettable that the 12 (were) arrested for alleged cultivation of cannabis,” the provincial government permanent secretary Chanda Kasolo told AFP.

“The arrest is really regrettable as it will delay the construction works,” said Kasolo.The Drug Enforcement Commission said in a statement that the 12 were arrested on Monday and 6.2 kilos of plants uprooted. Growing, dealing and consumption of cannabis for recreational purposes is illegal in Zambia. But growing cannabis for medicinal purposes is allowed provided permission is granted by the health ministry.

If convicted, the 12 face a maximum jail sentence of five years. Anti-Chinese sentiment in Zambia has grown over lucrative contracts awarded to Beijing, especially in the construction sector, and government borrowing from the Asian giant.

Cannabis belongs to the genus Cannabis in the family Cannabaceae and may include three species, C. sativa, C. indica, and C. ruderalis, (APG II system) or one variable species.It is typically a dioecious (each individual is either male or female) annual plant.

C. sativa and C. indica generally grow tall, with some varieties reaching 4 metres, or 13 feet. Female plants produce tetrahydrocannabinol (THC) (up to 29% by weight) as the season changes from summer to autumn. C. ruderalis is very short, produces only trace amounts of THC, but is very rich in cannabidiol (CBD), which may be 40% of the cannabinoids in a plant and is an antagonist to THC, and it flowers independently of the photoperiod and according to age. However, commercial cross-bred hybrids containing both ruderalis, indica and/or sativa genes exist (usually called autoflowering).