Human rights group Amnesty International has called on Iran to halt the execution of two teenagers following their convictions for murder.
Iran continues to execute juveniles, say human rights groups
The two young men have had their sentences upheld by the supreme court and are at risk of imminent execution, the group says.
Amnesty describes Iran's continued execution of minors as "a growing concern".
Iran has denied that it carries out the execution of juveniles.
Sixteen-year-old Mostafa was convicted of killing a drunken man in Tehran, the rights group says.
Seventeen-year-old Sina was convicted of a drug-related murder that also took place in Tehran, Amnesty says.
Iran is a signatory to the International Convention on Civil and Political Rights - which include a promise not execute anyone under the age of 18.
"Iran's defiance of the international ban on executing child offenders is a growing concern and calls into question its willingness to abide by international human rights standards, " said Amnesty International UK Director Kate Allen.
Iran has executed at least seven child offenders in 2005, according to Amnesty.
Another pressure group, Human Rights Watch, criticised Iran in July over the public hanging of two youths convicted of still unclear sexual offences.