(Reuters) – Petra Diamonds has suspended operations at its Williamson mine in Tanzania for up to three months after a wall of the tailings dam at the site was breached earlier this week, the company said on Thursday. Petra Diamonds, which operates three mines in South Africa as well as Tanzania’s biggest diamond mine, said there had been no fatalities as a result of the incident and three minor injuries had been reported, adding a probe was underway to establish the cause of the breach. A total of 13 dwellings have been affected by the breach, with those impacted getting aid and accommodation,…