A Papua New Guinea human rights group says one person was shot and killed, and another critically wounded in another attack at a controversial gold mine in Enga province.
The Akale Tangi Association, which is based in the area surrounding the Porgera mine, said the incident happened on Sunday, when guards opened fire on two people panning for gold on mine property.
The mine and its major shareholder, Canadian company Barrick, have been consistently criticised for human rights abuses in neighbouring villages, particularly at the hands of security contractors.
The association's executive officer, McDiyan Robert Yapari, said he had met with local police and written to Barrick about Sunday's incident, but he had little hope of an outcome.
He said the government and Barrick had for years promised investigations and action to address human rights concerns, but next to nothing had happened on the ground.
"We have written so many letters, the attention of Porgera and gross human rights violations has already reached the United Nations High Commissioner for Human Rights," Mr Yapari said.
"All these issues of human rights abuse have been raised and Barrick purports to say the company is committed to protecting human rights, but according to us, it is a whole lot of bulls**t."