It was late Saturday when several four-wheel drive vehicles rolled to a stop before a sun-battered, taupe apartment building in the eastern Baghdad neighborhood of Zayounah. The cars deposited militants who filed inside the widely known house of prostitution. In the militants’ hands were reportedly silenced guns.

Later, after the killing was done, Agence France-Presse said a single warning clung to a door: “This is the fate of any prostitution.”

The images gathered of that fate are snapshots of terrible carnage, each more chilling than the last. One shows the bloody bodies of eight young women amid discarded furniture. Another reveals five women who died in one another’s arms inside a bathroom. Three more bodies were splayed along the floor, their hair wild and matted.

In all, anywhere from 20 to 29 alleged prostitutes were killed in a massacre that also claimed the lives of several men. No one appears to know what happened: who the killers were, why they did this, who ordered it. In a city besieged by an encroaching Sunni army that has proclaimed a modern Caliphate, it looked on Monday as though those questions wouldn’t be answered. Residents told AFP that every few months prostitutes are found murdered in those apartments. And nothing is ever done.

“If a person got shot right next to a policeman, they wouldn’t say anything,” one shopkeeper who requested anonymity explained to the news agency. “They’re afraid. It’s the rule of the strong over the weak.”

However rough life is for sex workers elsewhere in the world, it’s rougher in Iraq. According to a review of journalistic, academic and aid agency accounts, theirs is a precarious economic existence made worse by perpetual warfare, regime change and the threat of summary executions and beheadings. In 2003, the U.S. State Department reported Iraqi militants, under the auspices of fighting prostitution, “beheaded in public more than 200 women throughout the country, dumping their severed heads at the families’ doorsteps. Many families have been required to display the victim’s head on their outside fences for several days.”

Analysts agree refugees are among the most susceptible to human trafficking, and Iraq has loosed hundreds of thousands of refugees in decades of unrest. The Organization of Women’s Freedom in Iraq reported that “an estimated 4,000 Iraqi women, one-fifth of whom are under 18, have disappeared [in broad daylight] since the 2003 invasion; many are believed to have been trafficked.” Some estimates said an additional 50,000 Iraqi women and girls were then forced into Syria’s sex trade.

But it wasn’t always that way. After the nation was founded in the late 1950s, the Organization of Women’s Freedom in Iraq said it was home to something similar to a regulated sex “trade. … There was a strong women’s movement on the ground.” When the Baathist regime swept into power in 1963, however, it ushered in laws that made prostitution illegal. Then came the implementation of economic sanctions on Saddam Hussein’s Iraq — and scores of desperate women were pushed into the industry.

“A starvation-style economy translated into exploitation of women in the workplaces,” the report said. “Although women were a big part of the public work force, their monthly salary became equivalent to a few dollars. A huge population of widowed single mothers started to practice individual and hidden prostitution in workplace or in neighborhoods for survival.”

That survival became even harder in the subsequent crackdowns and honor killings that claimed at least 9,000 Kurdish women within nine years — and that was still before the U.S.-led invasion shattered the country. In the years after, “families keep their girls inside, not only to keep them from being assaulted or killed, but to prevent them from being kidnapped by organized prostitution rings,” wrote analyst Debra McNutt in Common Dreams. “Gangs are also forcing some families to sell their children into sex slavery.”

That happened to a 15-year-old girl Human Rights Watch calls “Muna B.” She said men abducted her on May 11, 2003, along with her two sisters, age 11 and 16. “They did bad things to my sister,” she told the aid agency. “She told me that they had slept with her; she was crying. She only told me about that one night, and she said that all [four men] did it.”

The killings did not stop after Iraqi Prime Minister Nouri al-Maliki came to power. In some ways, they got worse as religious fanaticism crept into certain ministries. The Ministry of Interior “openly managed mass killings of prostitutes in Al Battaween in central Baghdad,” according to Organization of Women’s Freedom in Iraq. In July 2006, six alleged prostitutes and one man were executed in Baghdad by armed militants. More mass killings of women accused of prostitution also reportedly occurred in the southern cities of Basra and Umara between 2006 and 2008.

Today, the sex trade continues to thrive in Baghdad, Al-Monitor said, a precarious system hinging on older prostitutes called “sheikha” who look after younger ones. Business is done in nightclubs or in individual residences. “This is how things are for prostitutes in Baghdad,” wrote journalist Ali al-Saray. “Aliases are part of the precautions they take in a society that chases them down but derives pleasure from them at the same time.”

The journalist then asked one worker named Wardah, who has a 4-year-old son and said she “pleasures anyone who pays,” whether anything can dismantle the trade. “This,” she replied, “is just a dream.”