A U.S.-based rights group says Iran has carried out more secret executions at a prison where the practice was criticized in a recent UN report.



The International Campaign for Human Rights in Iran said the executions were carried out at Vakilabad prison in Mashhad in recent months.



Group spokesman Hadi Ghaemi told RFE/RL's Radio Farda on May 25 that "We have been able to confirm through local sources that executions have been performed secretly in Vakilabad prison since March 2011."



He said some 70 people were executed over that period without having been informed in advance of their imminent death.



Ghaemi said the death sentences are carried out after the sentences are forwarded by chief prosecutor Mohseni Ejei to the Mashad regional prosecutor. He blamed Ejei for the failure to inform prisoners or their families before the sentences are carried out.



Ghaemi questioned claims that most of the 1,000 people executed over the past 18 months were sentenced for drug-related crimes, noting that no statistics have been released. But he said his organization has compiled statistics for the number of prisoners executed at Vakilabad, a huge detention center housing some 10,000 prisoners.



He said executions also continue at the Karoon, Birjand, and Ahva prisons. He said the number of executions at Vakilabad may be higher because Mashhad borders on Afghanistan and is therefore on a major drug-trafficking route.



Ghaemi said the Iranian authorities have admitted to the UN that unannounced executions take place but that they understate the actual number.



He expressed concern that executions for drug-related crimes have not resulted in a decline in drug use in Iran, and that some of those executed may in fact be innocent.



In a report to the UN Human Rights Council in Geneva in March, UN Secretary-General Ban Ki-moon voiced concern about the human rights situation in Iran, including the executions of drug traffickers. The report said some 60 people had been executed in Mashhad in July.