GENEVA (AFP) - The United Nations on Tuesday decried numerous executions of civilians in Iraq by the Islamic State in Iraq and Syria (ISIS) group, warning that educated women appeared to be especially at risk.

The extremist group is showing a "monstrous disregard for human life" in the areas it controls in Iraq, the UN human rights office said.

The group, which controls large swathes of territory in Iraq and in neighbouring war-ravaged Syria, last week published pictures of the "crucifixions" of two men accused of being bandits, and of a woman being stoned to death, allegedly for adultery.

Numerous other women have also reportedly been executed recently in ISIS-controlled areas, including Mosul, spokesman Ravina Shamdasani told reporters.

She said "educated, professional women, particularly women who have run as candidates in elections for public office, seem to be particularly at risk".

"In just the first two weeks of this year, reports indicate that three female lawyers were executed," Ms Shamdasani said.

A number of other groups are also targeted by the militants, Ms Shamdasani said, pointing to "the ruthless murder of two men, who were thrown off the top of a building after having been accused of homosexual acts by a so-called court in Mosul".

Minorities are not the only ones suffering, with ISIS meting out "cruel and inhuman punishments" to anyone accused of violating its "extremist interpretations of Islamic syariah law, or for suspected disloyalty", she said.

Four doctors were recently killed in central Mosul, allegedly after refusing to treat ISIS fighters.

The group also reportedly executed 15 civilians in front of a large crowd in Fallujah on Jan 1 on suspicion they had cooperated with Iraqi security forces, and 14 more in a public square in Dour, north of Tikrit, for refusing to pledge allegiance to ISIS, Ms Shamdasani said.