Authorities in Ghana have arrested 124 Chinese citizens for illegal gold mining, shedding light on perceived social and environmental challenges posed by China’s growing presence on the resource-rich continent.

Local police in the capital Accra detained the suspected illegal miners who are thought to now be held at an immigration detention center in the city, China’s official Xinhua news agency reported, citing Francis Palmdeti, the head of the Ghana immigration service.

The Chinese embassy in Accra lodged representations to the west African country over the arrests, demanding Ghanian security authorities ensure the Chinese citizens’ legal rights and safety.

The workers were allowed consular access and most were expected to be deported soon, Yu Jie, the political director at the Chinese embassy, told the Financial Times.

The number of Chinese miners in Ghana has grown rapidly in recent years, even as the country barred foreigners from working in small-scale mines reserved for local communities. Chinese presence has also drawn criticism from Ghanians for taking local jobs, polluting bodies of water, and making wider inroads than they are allowed.