GENEVA (Reuters) - The United Nations human rights office is “appalled” at the hanging of 38 prisoners in Iraq, a U.N. spokeswoman said on Friday, a day after the executions at a prison in the southern Iraqi city of Nassiriya.

“We are deeply shocked and appalled at the mass execution,” the spokeswoman, Liz Throssell, told a regular U.N. briefing in Geneva, adding that the human rights office had “huge concerns” about Iraq’s use of the death penalty and - not for the first time - urged the government to halt all executions.

“Given the flaws of the Iraqi justice system, it also appears extremely doubtful that strict due process and fair trial guarantees were followed in these 38 cases. This raises the prospect of irreversible miscarriages of justice and violations of the right to life.”

The 38 male prisoners were convicted by Iraq’s judiciary for terrorism-related crimes, she said. She did not have information on their ages or nationalities.

In September, Iraq hanged 42 prisoners in a single day, and the U.N. has learned of 106 executions this year, Throssell said. Last year the Ministry of Justice announced 88 executions, but the U.N. believes the number may have been as high as 116.

The world body had repeatedly asked the Ministry of Justice for data about prisoners, sentencing and executions but no such information had been provided since 2015, she said.

Previously the United Nations had spoken of about 1,200 people being on death row, but it was now impossible to confirm that information, she said.

The Justice Ministry said in a statement on Thursday that all those convicted were members of Islamic State. Officials have said all the appeal options available to the condemned had been exhausted, according to the statement.