Image copyright Reuters Image caption The most recent report from Amnesty International looks at the Burakh border region between Afghanistan and Pakistan.
The US and other countries are concerned by the recent reports of summary killings in Afghanistan and other areas, says the National Security Council.
A statement said “extrajudicial killings, disappearances and enforced disappearances violate both international law and the Afghan constitution”.
It also said that such actions “are alien to the Afghan culture”.
Amnesty International says Afghan soldiers and police have executed civilians over the past few months in the border area.
It also reports that at least 868 Afghans died in brutal mistreatment in Iranian custody during the last year.
Foreign Policy magazine published the statement from the National Security Council on Friday, saying it was “following up on numerous reporting in the US media that [Afghanistan] appears to be on the brink of an ethnic civil war”.
The NSC called on Afghan President Ashraf Ghani and all stakeholders “to respect their constitutional and legal obligations to protect and promote the human rights of all Afghans”.
This came days after the NSC issued its own statement that urged the government “to reaffirm that all law-enforcement agencies in Afghanistan, including the security forces, comply with internationally recognised standards for conduct and to refrain from committing gross human rights violations”.
In Afghanistan, President Ghani’s government has faced criticism in recent months from all sides over the performance of security forces.
And on 8 August, a senior United Nations (UN) official accused the Taliban of killing civilians in air strikes and of denying those claims to Pakistani government officials.
Amnesty says it has received reports of two dozen people being killed by Afghan security forces in the border region of Burakh, which is near the border with Pakistan.
The latest report also includes a claim by the NDS – the intelligence agency – that Taliban and Haqqani network fighters kidnapped 115 prisoners in the border area in the last 18 months, took most of them to a location near the Pakistani border, and executed 19 of them when they were blindfolded.
Rights groups have also documented dozens of Taliban kidnapping and killing civilians in villages in western and eastern Afghanistan since December 2017.
Amnesty says the NDS denies involvement in such cases but details of the incidents suggested it was involved.
“The abuses documented in this report are extremely serious and deeply condemnable,” said Babar Khan, Afghanistan’s top human rights official.
“Independent investigations of cases in question, and if they are proven, criminal prosecutions are necessary to bring justice to victims.”
A statement from the NDS said it would launch an investigation into the allegations.
In neighbouring Pakistan, the UK Foreign Office said it is “deeply concerned by these allegations, and calls on all parties to ensure that civilians are protected”.
“Pakistan should take swift action to ensure that those responsible for this violence are identified and held to account,” said a spokesperson.
The Foreign Office has also said that it called on the Afghan government to urgently investigate the incidents and to call for a “prompt and effective” investigation and to prosecute the perpetrators.
In Iran, the state-owned Press TV said the information was based on 13 detainees’ testimonies, as well as video footage.
“A number of women who were detained by the Iranian authorities claimed that their torture by a number of interrogators in Tehran’s Tora prison had included being tied to the wall and beaten up,” said the report.
On Friday, Iranian Foreign Minister Mohammad Javad Zarif said the torture allegations were untrue.
“Iran is proud of its dedicated and professional judiciary [and] our judicial system does not use such torture methods,” he said in an interview with the state-run broadcaster.
While expressing sympathy for any victims, Mr Zarif said it ” is extremely unfair and … utterly baseless” to blame Iran, which he said is an ally of the international community.