"In the course of the past week, the ministry has carried out the death sentences handed down against 42 people, one of them a woman, who were all convicted of terrorism offences, in accordance with Article 4 of the anti-terrorism law," Hassan al-Shammari said.
The latest executions take to at least 132 the number of people who have been put to death in Iraq this year, according to an AFP tally based on reports from the justice ministry and officials.
The growing resort to the death penalty comes as violence in Iraq has reached a level not seen since 2008, when the country was just emerging from a brutal sectarian conflict.
More than 230 people have been killed so far this month, and more than 4,900 since the beginning of the year, according to AFP figures based on security and medical sources.
But the executions, which in Iraq are usually carried out by hanging, have drawn widespread condemnation from the European Union, the United Nations and human rights watchdogs.
She highlighted "numerous convictions based on confessions obtained under torture and ill-treatment, a weak judiciary and trial proceedings that fall short of international standards."
"The application of the death penalty in these circumstances is unconscionable, as any miscarriage of justice as a result of capital punishment cannot be undone," Pillay said.
But the justice minister insisted that the executions were only carried out after an exhaustive legal process.
"The death sentences handed down against those condemned were the object of multiple appeals... To make sure of the soundness of the convictions," the minister said.