Iranian authorities on Sunday hanged 12 people convicted of various serious crimes in the southern city of Shiraz, Mehr news agency reported.
Seven of those executed were found guilty of drug trafficking. The other five were convicted of rape, kidnapping and armed robbery.
The deaths bring to 15 the number of hangings carried out in Iran so far this year, according to an AFP tally based on media reports.
The European Union last week expressed concern at the number of executions held in Iran in 2011, and called for "thousands" of convicts on death row to have their sentence commuted.
Last year, 277 people were hanged, according to an AFP tally.
In 2010, the rights group Human Rights Watch counted 388 executions, while Amnesty International counted 252.
The Islamic republic is one of the world's main practitioners of capital punishment, a distinction shared with China, Saudi Arabia and the United States.
Iran says the death penalty is essential to maintain law and order, and that it is applied only after exhaustive judicial proceedings.