United Nations human rights experts are calling on Iran to halt what they call an "abrupt surge" in hangings in the country since the start of 2014.
The call is contained in a joint statement from the UN special rapporteur for human rights in Iran, Ahmed Shaheed, and the UN special rapporteur on summary executions, Christof Heyns.
The statement described Iranian authorities as carrying out the death penalty on prisoners with "alarming frequency."
The statement said at least 40 people have reportedly been hanged in Iran in the first two weeks of January, with at least 33 executions reported in the past week.
It said 652 executions were reported to have been carried out in Iran in 2013, including at least 28 women and a number of political prisoners.