(CNN) The photographs released by ISIS in its stronghold of Raqqa are dated March 2015. The first ones show a large crowd, mostly men, but also among them a handful of women and children, all looking up.

Three men on top of a building, faces covered in black balaclavas, stand on either side of their victim, while a fourth seems to be taking a photo or video.

Their victim is thrown off the building. In the last photograph, he is seen face down, surrounded by a small crowd of men, most carrying weapons, some with rocks in their hands. The caption reads "stoned to death."

The victim brutally killed because he was accused of being gay.

There are at least half a dozen documented cases of men being similarly killed by ISIS . What's even more sickening for Nour, a gay Syrian man, is the onlookers' reaction.

One gay couple CNN spoke to said they fled Syria after a car tried to run them over.

"It's too much to watch, and people are just standing there in these images and watching, and they are not doing anything, and their facial expressions are really scary because they are not even scared of what is going on," says Nour, who's also an LGBT rights activist. "They might be a little bit excited or maybe happy to get rid of homosexuals in the city."

Though in Istanbul, fear of persecution continues to haunt Nour, who asked us to conceal his identity as he waits and hopes for asylum in America and continues to campaign for rights for people who are LGBT -- lesbian, gay, bisexual and trans.

A history of abuse

As a teenager, over a decade ago, Nour suffered because of his sexuality.

"The worst bullying was at school," he remembers. "I was approached in the street a number of times, verbally abused and sometimes physically abused."

There was no one to protect him. His family rejected his sexual orientation, his country criminalized it.

Article 520 of the Syrian Penal Code of 1949 states: "Any unnatural sexual intercourse shall be punished with a term of imprisonment of up to three years."

Nour left Syria in 2012, before ISIS took over huge swaths of the country, after seeing a video of two men being beheaded. According to the voice on the clip, they are accused of being spies. Then toward the end, the voice speaks about "shaking the throne of God."

"Whenever we hear this in video or audio, we know that this is exactly meant for gay people," he says. "It was the moment of clarity, the moment of understanding; this place is not safe anymore."

The pictures released by ISIS and other videos refer to gay men as the tribe of Lot, who, according to readings of the Quran and the hadith, or prophetic traditions, sinned by refusing Prophet Lot's call to cease their homosexual activity and led to the destruction of Sodom. One hadith states, "When a man mounts another man, the throne of God shakes."

Since the revolution turned war in Syria , the situation for the nation's LGBT community has become even more dire.

"LGBT people in Syria need help, and they need to be supported. We tried to reach out to some groups, international entities, and they said that LGBT people in Syria are not our priority, and that would mean that our lives are not worthy for them to rescue," Nour says.

This week, the International Gay and Lesbian Human Rights Commission, a nongovernmental organization based in New York, started "Don't Turn Away," an awareness-raising campaign calling for action to protect LGBT Syrians and Iraqis from ISIS' merciless brutality.

On its website, the group states, "What is clear is the Islamic State's intent -- to spread terror among an already persecuted population in the region and to warn against any kind of 'moral' transgression."

The commission is calling on governments and the United Nations High Commissioner for Refugees to expedite resettlement and refugee applications for LGBTs.

Driven away by threats

Sami and his partner are among those waiting. Dressed in matching outfits, they already consider themselves married, laughing about how they first met online. They too, like Nour, don't want their identities revealed.

When Sami's family found out about his relationship, he says, his brother tried to beat him up. He started to receive threatening phone calls from family and strangers.

This past summer, while the couple was walking in the streets in Damascus, a car tried to run them over.

"I was able to pull myself away, but my husband couldn't," Sami recalls. "The car hit his leg and he fell to the ground."

There is no doubt that it was a deliberate attempt to kill them. Two hours after the attack, Sami's phone rang.

"There was a man who said this time you could have made it, you could have survived, but the next time you will not."

The couple fled to Turkey a few months ago, but they can't shake the fear that their relationship could cost them their lives.

They share housing with other Syrian refugees, where they have to continue to pretend that they are straight. When the ISIS photographs emerged, one of their housemates made a sickening comment.

"He made an absurd joke about how he was so amused, had too much fun watching homosexuals. He says now gay men can fly."

They say they will never return to Syria. And neither will Nour.

"It's too damaging for my psychological state, because I have been abused too much from my family, friends, school. It's not safe for me psychologically or physically," he says.