A third of Afghan detainees have been allegedly tortured or mistreated during detention, the UN said in its latest report.

According to the UN Assistance Mission in Afghanistan (UNAMA), the number of detainees saying they had been ill-treated or tortured in the past two years was 278 out of 790 that were interviewed.

Most of the interviewees were younger than 18. They were detained in 128 facilities spread across the country's 34 provinces.

The report listed 16 different torture methods, including severe beatings with pipes, suspension from walls or ceilings, electric shocks and near-asphyxiation.

The majority of the detainees tortured were suspected Taliban terrorists.

Subjecting detainees to torture is a grave violation of the rights to life and freedom guaranteed by the International Covenant on Civil and Political Rights, of which Afghanistan is a signatory.

The number of those who said they were subjected to torture or ill treatment was 14% lower than in the previous report, the UN said.

"The Government of Afghanistan's efforts to prevent torture and ill-treatment have shown some progress over the last two years," said the UN Secretary-General's Special Representative for Afghanistan and head of UNAMA, Nicholas Haysom.

"More remains to be done, however, and I welcome the new administration's immediate attention to end these practices.

"In particular, UNAMA welcomes the incoming Government's commitment to implement a new national plan on elimination of torture," Haysom continued. "We support – and can assist as requested – this comprehensive approach to eliminate torture and ill-treatment in Government of Afghanistan facilities."

According to the report, the decrease in the number of torture and ill-treatment cases is due to government policies banning the practices and increasing inspection visits to detention facilities.

However, perpetrators still go largely unpunished.

"Continuing impunity for the use of torture allows torture to continue,"said the UNAMA Human Rights Director, Georgette Gagnon.

"Accountability – particularly the prosecution of both those who perpetrate and administer torture, and those who order or condone it – is a key means of signalling political commitment at the highest levels to end it."