Jakarta, Indonesia (CNN) -- Several people, including one American, were wounded Sunday when a convoy belonging to a U.S. mining company came under fire in the province of Papua, police said.
The convoy of two buses and four cars was carrying employees of PT Freeport, the largest copper and gold mining company in the country's eastern-most province.
"We're still investigating who's behind the shooting. This is the first case this year," said Agus Rianto of Papua police.
Three of the wounded were taken to the capital, Jakarta. Among them was the American citizen, police said.
The mining company put the number of wounded at nine, saying three of them required hospitalization. None were life-threatening injuries, the company said.
Production was not affected, Mindo Pangaribuan of PT Freeport Indonesia said.
The company has often been a target of attacks in recent years.
Papua residents have long resented the presence of PT Freeport in the province. They have criticized the environmental impact of the mining operations and the small share of revenues the province receives.
Attacks directed at the company killed an Australian mine technician and two Indonesians on July 11 and 12.
In 2008, a separatist group claimed responsibility for a series of bomb attacks in the area. No one died in the attacks, the state-run Antara news agency said.
In 2002, two American teachers and an Indonesian colleague who worked at the mine were shot dead in an attack, the news agency said.
CNN's Andy Saputra contributed to this report.