NATO officials in Afghanistan stopped transferring detainees to Afghan custody in several provinces this week in response to a U.N. investigation that found evidence of systematic torture at some detention centers, the military command said Tuesday night.

The move represents a serious setback for the United States and its allies in Afghanistan at a time when the international community is beginning to pull out troops and shift more responsibility for security to the Afghans.

The findings of a report on detainee abuse, which the U.N. mission here intends to make public in coming days, will probably embolden insurgent groups, which have sought to portray Afghan officials as lackeys of Western crusaders.

Senior NATO officials decided to stop transferring detainees to Afghan custody in several key provinces after human rights investigators with the United Nations briefed them on the findings. The review of detention facilities had been underway for nearly a year.

A NATO official, who spoke on the condition of anonymity to discuss the sensitive issue, called the detainee-transfer suspension “prudent” and said it will be in place until military officials “can verify the observations” in the report.

The U.N. team said it found evidence of widespread torture at five provincial facilities run by the Afghan intelligence agency, the National Directorate of Security, and two jails run by police, officials familiar with the findings said.

The NDS-run facilities where NATO has stopped sending detainees are in Khost, Laghman and Kapisa provinces, in the east; Herat, in the west; and Takhar, in the north. Transfers to the NDS’s counterterrorism jail in Kabul also were suspended.

The two affected police jails are in Uruzgan province in the south and Kunduz province in the northeast.

NATO suspended detainee transfers in Kandahar province, the Taliban’s birthplace, last month, also in response to credible allegations of detainee abuse.

The main spokesman for the NDS was out of the country Tuesday, and other officials at the agency declined to comment. NDS officials said they would hold a news conference Wednesday morning.

Dan McNorton, a spokesman for the U.N. mission in Afghanistan, said Tuesday night that senior Afghan officials were recently briefed on the review team’s conclusions.

“We understand they are taking the findings very seriously and are proposing a series of remedial actions,” he said. “Our findings indicate the mistreatment of detainees is not institutional or government policy.”

The BBC, which disclosed the U.N. probe Tuesday night, reported that detainees told investigators that jailers suspended inmates in stress positions, subjected them to electric shocks, threatened them with sexual assault and beat them with rubber hoses.

Under Afghan law, the NDS is supposed to hold suspects for no more than 72 hours, but inmates are commonly kept in the agency’s detention facilities for lengthy periods without being charged.

The United States had hoped to transfer the country’s most high-profile prison, located at Bagram air base, to Afghan control by January 2012, but officials have decided that they cannot responsibly meet that deadline.