Worldwide, more than half of the victims of honour killings are tortured — a gruesome message to other women to remain subservient, according to an expert in the field.

Surprisingly, the use of torture in such murders is much more prevalent in Europe than anywhere else.

Two-thirds of the victims in Europe were tortured, compared to half in the Muslim world and about one-third in North America.

The findings are in a report on honour killings by U.S. academic and author Phyllis Chesler, in the spring edition of Middle East Quarterly.

Torturous deaths include being gang-raped before being killed or being bludgeoned, stabbed repeatedly, stoned, burned to death or beheaded.

And honour killings are a family collaboration, writes Chesler.

In the 230 cases she analyzed, two-thirds of the victims were killed by their families of origin, including fathers, mothers, brothers, grandfathers, uncles and male cousins.

More than 90% of the honour killings Chesler studied were Muslim-on-Muslim crimes.

The level of "primal, sadistic or barbaric savagery" is akin to some of the murders in the West perpetrated by serial killers against prostitutes, she writes.

It suggests that the devaluation of girls and women, normalized child abuse — including arranged child marriages — sexual repression and the increasingly violent ideology of jihad are leading to "murderous levels" of aggression towards women, she adds.

"One only has to kill a few girls and women to keep the others in line," she observes.

"Honour killings are, in a sense, a form of domestic terrorism meant to ensure that Muslim women wear the Islamic veil, have Muslim babies and mingle only with other Muslims."

She rightfully dismisses those who suggest honour killings are the same as western domestic violence.

In the non-immigrant West, she notes, serious domestic violence exists but there is no cultural pattern of fathers specifically targeting or murdering their teenage or young adult daughters.

Nor do extended family members help plan, perpetrate and justify such killings, Chesler explains.

Domestic violence, used to keep a woman isolated and subjugated, doesn't reflect a western cultural or religious value, she writes.

Rather, it reflects the individual psychological pathology of the western batterer-murderer.

"On the other hand, an honour killing reflects the culture's values aimed at regulating female behaviour."

Furthermore, such values are not often condemned by major political and religious leaders in Muslim countries or in immigrant communities in the West, she charges.

"As long as Islamist groups continue to deny, minimize or obfuscate the problem, and government and police officials accept their inaccurate versions of reality, women will continue to be killed for honour in the West."

In an interview Thursday, Chesler said the West needs to set up witness protection programs for the intended targets of honour crimes and women's shelters need staff specially trained in the tactics of honour killings, so targeted women aren't lured back home.

A targeted woman faces the difficult task of creating a whole new life, Chesler warns. "She's lost her extended family forever because they will never quit the desire to kill her."

Citizens or not, adds Chesler, the perpetrators and their families should be deported.

"What would stop an honour killing? If they understood that all of them are going to be deported, they might not do it."

Are there any women out there who have escaped planned honour crimes and left their families? I'd like to hear your stories.