British special forces carried out a series of killings of unarmed men and detainees in suspicious circumstances in Afghanistan, according to the BBC. Reports obtained by the news organization suggest operatives in just one unit from the Special Air Service (SAS) may have unlawfully killed 54 people over the course of a six-month tour. The BBC also alleges to have uncovered evidence that Gen. Sir Mark Carleton-Smith, the former head of U.K. Special Forces, failed to give vital evidence on the killings to a murder inquiry run by the Royal Military Police. Witnesses to the alleged crimes say members of the accused SAS squadron would use “drop weapons”—AK-47s planted at the scene of a killing—to justify the shooting of an unarmed person.