JAKARTA, Indonesia — Crowned with spiky feathered headdresses and daubed with face paint, scores of protesters gathered outside the Jakarta offices of an American mining giant last week, chanting, waving signs and throwing uncertainty into global commodities markets.

The traditional garb was meant to make it clear whom they represented: the people of West Papua, site of Freeport-McMoRan’s Grasberg mine — one of the world’s largest sources of gold and copper. Their shouted slogans made it equally clear what they wanted.

“Freeport must be shut down!” the crowd chanted.

It was a refrain that, in recent months, has resonated throughout Indonesia. Less than a week earlier, dozens of students from a different organization — dressed in red and white, Indonesia’s national colors — gathered outside the same office, calling for the government to take a firm hand with the company.

“Freeport hasn’t brought prosperity. It’s just destroyed the natural environment,” said Surya Anta, national coordinator for the Indonesian People’s Front for West Papua. His organization helped organize anti-Freeport protests in 17 cities around the country.