More than 2,000 people have been killed in Iran since President Hassan Rouhani was elected in 2013. IBTimes UK spoke with London-based NGO Reprieve, which recently published a report highlighting a correlation between anti-drug projects in Iran sponsored by European countries and the spike of executions in Middle Eastern nations.

Alongside the Reprieve report, human right groups have warned that several executions in Iran, mainly carried out by hanging, are in breach of both domestic and international laws. In July, NGO Iran Human Rights (IHR) warned Iran executed at least one juvenile offender in 2015. Javad Saberi was hanged after being convicted of murder, despite the fact he suffered from mental illness.

In another interview with IBTimes UK, IHR warned that Iran was executing an estimate three people per day. The NGO said the majority of executions carried out in the first half of 2015, took place in Ghezel Hesar, Iran's largest state prison with 20,000 prisoners (four times its official capacity), where dozens of inmates were executed in June after they gathered in the prison yard to ask Iran's Supreme Leader Ali Khamenei for forgiveness.

Iran allows capital punishment for juveniles in case of "qesas" (retribution-in-kind) and "hodoud" (offences and punishments for which there are fixed penalties under Islamic law). However, article 91 of the Islamic Penal Code excludes the death penalty if the juvenile offender did not understand the nature of the crime or its consequences, or if there are doubts about their mental capacity.

The high-profile case of Saman Naseem, a 24-year-old man sentenced to death at the age of 17 and whose whereabouts are unknown today, prompted the international community to criticise Iran after it announced his execution.