(IDEX Online) - Petra Diamonds has been accused of breaching human rights at its Williamson diamond mine, in Tanzania.The UK-listed miner, which put itself up for sale last month, today said that lawyers had filed complaints against it and mine operators Williamson Diamonds Limited (WDL) alleging "human rights violations, personal injuries and deaths" on behalf of 32 anonymous individuals.The UK-based law firm, Leigh Day, filed claims in the High Court of England and Wales, though they have yet to be served on Petra or WDL.In its letter before claim, it expressed an interest in alternative dispute resolution methods, including mediation.Petra said it took the allegations "extremely seriously" and both it and WDL would be carrying out their own investigations.It also said that it had previously highlighted concerns about illegal mining activity at Williamson (pictured), a large open pit mine that is hard to secure and covers more than 30km2.In a statement Petra said: "The claims are understood to allege that Petra and WDL are liable for human rights violations, personal injuries and deaths suffered by these anonymous individuals at and surrounding the mine, arising from the mine's security operations."