BAGHDAD, Iraq (CNN) -- Hundreds of gay men have been tortured and killed in Iraq in recent months, some by the nation's security forces, Human Rights Watch said Monday.

Iraqi clerics say homosexuality must be eradicated but warn against anti-gay violence.

Interviews with doctors indicate hundreds of men had been killed, but the exact number was unclear because of the stigma associated with homosexuality in Iraq, the New York-based watchdog group said in its report.

"Iraq's leaders are supposed to defend all Iraqis, not abandon them to armed agents of hate," said Scott Long, director of the Lesbian, Gay, Bisexual and Transgender Rights Program at Human Rights Watch. "Turning a blind eye to torture and murder threatens the rights and life of every Iraqi."

Four victims who spoke to CNN gave accounts of the attacks, which they say have intensified in the past few months.

"In 2004, militias and unknown groups started to go after the gays ... but the peak was six months ago," said Qaisar, who uses a pseudonym for fear of reprisal. "It has become wide scale war against gays in Iraq."

Iraqi officials acknowledged that the nation's culture stigmatizes homosexuality, but said the government does not condone such attacks. Authorities are unable to provide homosexuals with special protection, said government spokesman Ali al-Dabbagh.

According to Human Rights Watch, which is urging a government crackdown, attackers target people on the streets or storm homes, where they conduct interrogations and demand names of suspected gay men. Many end up in hospitals and morgues, the organization said, basing its conclusion on reports from doctors.

Men have been threatened with "honor killings" by relatives worried that their "unmanly behavior" will ruin the family's reputation, Human Rights Watch said. Watch Iraqi men discuss attacks »

Killings, kidnappings and torture of those suspected of homosexual conduct have intensified in areas such as the Baghdad neighborhood of Sadr City, the watchdog said.

"The Shiite people started this war and especially what happened in Sadr City," Qaisar said, adding that his sister-in-law had warned him against going to the area.

Muqtada al-Sadr's Mahdi Army militia, which is active in Sadr City, has joined in the attacks and defends its actions as a way to stop the "feminization" of Iraqi men, the report said.

"We have testimony that indicates that the nation's security forces are taking part in the attacks," Long said.

The group interviewed more than 50 people who gave accounts of abuses, beatings and stops at security checkpoints, he said.

"When the gay killings started and when they started go(ing) after them at checkpoints ... we started to change our look," said Basim, who also used a pseudonym.

"These killings point to the continuing and lethal failure of Iraq's post-occupation authorities to establish the rule of law and protect their citizens," said Rasha Moumneh, Middle East researcher for Human Rights Watch.

A provision from the Saddam Hussein era endorses crimes committed "with honorable motives," according to the organization.

The government spokesman said the provision was popular during the Saddam era, but is not used today. He added that there is a push to educate police about human rights.

Attacks against civilians, including homosexuals, are not allowed, al-Dabbagh said.

All About Human Rights Watch • Muqtada al-Sadr