The scribbled note was brief. Karazan had to die because he was gay. In the new Baghdad, his sexuality warranted execution by the religious militias.

The father was told that if he did not hand his son over, other family members would be killed.

What scares the city’s residents is how the fanatics’ list of enemies is growing. It includes girls who refuse to cover their hair, boys who wear theirs too long, booksellers, liberal professors and prostitutes. Three shops known to sell alcohol were bombed yesterday in the Karrada shopping district.

In this atmosphere of intolerance and intimidation, the militias have made no secret of their hatred of homosexuals.

The man who threatened Karazan said that he was a member of the Taib (Wolf) Brigade, a commando group reportedly infiltrated by the armed wing of the hardline Shia party the Supreme Council for Islamic Revolution in Iraq. Its orders come from fundamentalist clerics.

With his skin-tight clothes and long blonde hair, Karazan, a 23-year-old arts student, stood out in the Shia neighbourhood of al-Dura. He told The Times: “A number of my gay friends have been murdered, so I took this warning seriously.” The family fled this month to a suburb north of the city centre.

Karazan cut his hair short and dyed it black, but he is still too frightened to venture out. His partner is in the Iraqi Army. With little money and no valid passport, he does not know how he can flee abroad.

Ali Hili, who ran a gay nightclub in Baghdad but fled to Britain this year after receiving death threats, says that he knows of more than 40 men murdered in recent months. “Badr militants used chatrooms to lure them to a rendezvous and then kill them,” he said.

He described a co-ordinated attack on one couple: 38-year-old Karim survived a hand- grenade attack on his home in al-Jameha, but his partner, Ali, was shot dead when he tried to flee his house near by.

Haydar Faiek, 40, a transsexual, was beaten and burnt to death last September in Karrada’s main street. Ammar, 27, was abducted and shot in the head in January.

Meanwhile, a 34-year-old theatre actor, who would only give his name as Bashar, has gone into hiding after a death threat. Two close members of his family have been murdered by militants, who say they will carry on killing his relatives until he turns himself in.

The Interior Ministry says that it is investigating a claim by gay activists that a 14-year-old male prostitute was killed in al-Dura last month by men in police uniforms. The gunmen told the boy’s father that he was executed for “corrupting the community”.

Times Recommends

• The truth behind Obama's meteoric ascent
• Christians flee Iraq amid religious cleansing
• Aid agencies: 5m face starvation in Zimbabwe