An environmental activist in Sudan was questioned by security services this week in connection with ongoing protests over the use of dangerous cyanide in the gold industry in and around South Kordofan state.

Radio Dabanga reports that Ibrahim Naima was taken to the National Intelligence and Security Services (NISS) offices in Abu Jubeiha, after authorities found a statement calling for armed resistance of the gold factories circulating in the region.

Naima told the news outlet he was not involved with the statement, and he was ultimately released.

Opposition to the use of cyanide in gold mining and processing operations near village populations has met with increasing protest among residents who feel unsafe, and from the nationally accredited environmental committee that serves the region.

Committee spokesman Ahmad Mukhtar has said at least 11 companies are using cyanide while mining gold in South Kordofan state, and there are at least 30 companies doing business there.

Many of them are now doing so under police protection, following protests that included an arson attack on the El Hadaf mining company buildings and vehicles in Talodi in February. The Sudanese Ministry of Metals sent 190 police officers to protect facilities there, and in Abu Jubeiha and Kologi, the radio station said. In Kologi, large crowds again gathered at the gates as recently as Sunday.

In January, four days of activist protests against a planned mining operation in Sebu, in the northern part of the country, forced the government to withdraw the permit for the company.

Gold mining has taken off since 2015 and provides much-needed revenues to Sudan, which has found itself in economic isolation because of sanctions for years. The mining industry is poorly regulated, with the cyanide and mercury entering rivers and soil.

Dr. Yasser Hamouda, a chemical researcher in the United Kingdom, has warned that it takes less than two grams of cyanide to kill people and wildlife, who now are facing catastrophic environmental risk.