(IDEX Online) - A human rights watchdog claims seven people have been killed and 41 injured by security staff at Petra Diamond's Williamson mine, in Tanzania.It alleges there has been a catalog of "killings and brutal assaults" involving local artisanal miners since Petra acquired the deposit from De Beers in 2009. The government of Tanzania holds a 25 per cent stake in the mine.The report by RAID, a UK-based charity, claims people have been "shot with little or no warning, stabbed, detained, stripped, beaten, incarcerated for days in a filthy and cramped holding cell by the mine's entrance, deprived of food and medical treatment, and/or handcuffed to hospital beds at the mine's medical facility."The mine's approach to artisanal mining had been "ruthless and militaristic", it says."Based on extensive field research RAID has found evidence indicating that since Petra Diamonds acquired the Williamson mine in 2009, there have been at least seven killings and 41 assaults of local residents, many leading to life-changing injuries," says the report, based on more than 14 months of research and 118 interviews..RAID makes the claims in a 76-page report published today entitled The Deadly Cost of "Ethical Diamonds" - Human Rights Abuses at Petra Diamonds' Tanzanian Mine.In statement the UK-based miner as saying it found the allegations of human rights abuses to be "deeply concerning". It said it took the matter very seriously and had suspended the mine chief security officer and the support services manager at Williamson Diamonds Limited (WDL), the subsidiary that operates the mine.It also said it had been engaging and cooperating with RAID since being made aware of the allegations on 29 August 2020. "The company is working hard to address the allegations as a matter of urgency," it said. "A sub-committee of the board, comprised entirely of independent non-executive directors, has been formed to oversee the matter and an investigation has been initiated and is being carried out by a specialist external adviser in conjunction with the company's lawyers."The investigation is scheduled to be completed by the end of the calendar year and the committee will consider the outcome of the investigation and the recommendations to address any findings. This may include any required remedy or corrective action to be taken as a result of the investigation's conclusions."Pic shows the Williamson mine