A U.S. government watchdog says Afghan security forces remain "complicit" in the sexual abuse of young boys despite previous warnings and strict penalties for such activities laid out recently by Afghanistan's president.

The Special Inspector General for Afghanistan Reconstruction (SIGAR), an office that audits and monitors Afghan reconstruction projects, made the fresh allegations in a report released on July 30 that highlights Afghanistan's struggle to root out human rights violations within the U.S.-trained armed forces.

SIGAR said it had filed a classified report to Congress into claims of child sex abuse by the Afghan security forces and whether the American military was turning a blind eye to the practice.

SIGAR, created by Congress in 2008, and other groups have warned in the past about the resurrection of the practice of "bacha bazi" -- literally, dancing boys -- in which wealthy or powerful men exploit underage boys as sexual partners. The victims are often orphans or boys from poor families as young as 10.

Powerful religious and social conservative elements in Afghanistan have banned women from dancing in public, so young boys are sometimes dressed as girls and made to perform. The boys are often sexually abused and raped.

'Terrible Practice'

Human rights groups say the worst offenders include security forces, U.S.-trained militias, and former warlords and strongmen, who often act with impunity.

"Afghan officials remain complicit, especially in the sexual exploitation...of children by Afghan security forces," SIGAR said.

Under U.S. law, the Pentagon and the State Department are prohibited from providing assistance to any unit of a foreign country's security forces if there is credible information that the unit has committed any gross violations of human rights, according to SIGAR.

"The U.S. military has long known about the involvement of senior Afghan commanders and other figures in this terrible practice but has done little to curb it even as U.S. forces continue to train and fund Afghan forces," Patricia Gossman, a senior researcher on Afghanistan at Human Rights Watch (HRW), said.

"The U.S. has an obligation to do so and to stop supporting any Afghan forces who engage in this practice, investigate all reports of it, and press for prosecution of those responsible," she added.

There are about 8,400 U.S. soldiers in Afghanistan, providing training and assistance to Afghan security forces under the NATO mission.

The practice of bacha bazi has reportedly spread since the fall of the Taliban, who declared it un-Islamic. It has now spread from rural areas to big cities, including Kabul.

Strict Penalties

In February, President Ashraf Ghani laid out strict penalties against bacha bazi for the first time in a revised penal code. Punishments range from seven years in jail for sexual assault to the death penalty for aggravated cases in which more than one child is involved.

But the government has yet to present a time frame for when the revised penal code will be enforced.

In 2016, a former dancing boy told RFE/RL that he was kidnapped and taken to a village, where he said two men raped him. Faisal said he danced for two years before he turned 18, when most dancing boys are considered men and tossed aside.

The SIGAR report comes at a time when U.S. officials are describing Afghan security forces' battle against the Taliban as a "stalemate."

The report found that Afghan forces continue to suffer high casualty rates, with 2,531 killed in action and another 4,238 wounded between January 1 and May 8. SIGAR said at least 6,785 Afghan soldiers and police had been killed in the first 10 months of 2016.

SIGAR also said government forces control 59.7 percent of the country's 407 districts, the same as the last quarter, suggesting efforts to recapture territory lost to the Taliban and other militants have failed.