The government of Angola is making moves to push diamond miners out of the country to make the area available for commercial enterprises. According to a report from the Thomson Reuters Foundation, the majority of the affected miners are from the Democratic Republic of Congo, which borders Angola to the northeast.

Angola is the worlds fifth-largest supplier of diamonds, and the government is looking to exploit the county’s natural resource by opening mining operations to large companies.

The current push to send the miners back across the border began at the beginning of the month and is affecting approximately 200,000 Congolese. The large number of small-scale mining operations that are being disrupted could have potential implications for the world diamond supply; however, it’s not diamond production that is drawing international attention, but the use of force by the Angolan security forces.

Several of the affected Congolese have reported that the Angolan forces are using extreme violence to gain compliance and that several dozen of the miners have already been murdered by the security forces and their allies, the Chokwe tribe. Much of the violence is taking place in the town of Lucapa, in Lunda Norte province. According to Reuters, Lunda Norte is considered “diamond-rich.”

“There was a lot of violence in Lucapa,” said 28-year-old diamond miner Victor Tshambapoko, while speaking to Reuters. “The military was shooting at us while Chokwe were killing people with machetes. They jointly killed more than a dozen people.”

Several witnesses reported similarly gruesome scenarios.

“Suddenly on Monday (last week) we saw youths from the Chokwe community with Angolan policemen starting to burn the homes of those perceived to be foreigners,” said one Congolese woman while speaking to Agence France Presse (AFP). “When they came to our house, they attacked my husband with a machete and we were forced to flee taking whatever little we could carry,” she said.

Angolan authorities have denied these claims, and state they are unable to cope with the massive influx of migrants crossing over the border. About 1,000 Congolese are crossing over the border every hour, many of which have already been deported before.

“How can these people refuse to go back to their country? It makes me laugh,” said one Angolan official while speaking to AFP.

Although Congolese have long sought to enter Angola to seek better economic opportunities, many of the affected are small-time artisanal miners. According to the Diamond Development Initiative (DDI), a nonprofit group which advocates on behalf of artisan diamond miners, this type of mining is done by hand, using “rudimentary equipment” to dig for the stones. An artisanal miner is responsible for finding about one in every five diamonds sold commercially around the globe.

“Small-scale mining is of great economic and social significance,” DDI says. The group also claims that there are approximately 13 million people who participate in artisan mining around the world and that the practice supports between 80 and 100 million people.

While the practice can benefit those who partake in it, artisanal mining is not without its criticism.

“Concerns range from the use of child labour and the potential for environmental damage to the use of mine revenue to finance conflict,” said a spokesman for DDI in a statement.