An employee of the British consulate in Hong Kong is being detained for violating the law, Beijing confirmed on Wednesday.

Police in Shenzhen, South China's Guangdong province, imposed a penalty of a 15-day administrative detention on the employee, who violated China's Public Security Administration Punishment Law, Foreign Ministry spokesman Geng Shuang quoted sources as saying.

Regarding the UK's expression of concern over the detention, Geng said the man is a Hong Kong citizen, not a British citizen, thus the incident is purely within the sphere of China's domestic affairs.

China has lodged solemn representations to the UK, which "released a series of erroneous remarks over issues concerning Hong Kong", Geng said, and urged the UK to "stop gesticulating over the issues and stirring troubles".