A report from UN Secretary-General Antonio Guterres to the UN Security Council reportedly accuses the fundamentalist Taliban of dozens of revenge killings since the Taliban swept into control of much of Afghanistan in August.
Reuters news agency on January 30 cited a copy it obtained of the report, which cites declining conditions since a Taliban-led government arose in September.
In it, Guterres also urges the Security Council to back a restructuring of the UN's effort to alleviate the situation and the establishment of a new human rights monitoring unit for Afghanistan.
It is the latest dire warning from the international community about humanitarian and other mounting crises for Afghanistan's 39 million people
"An entire complex social and economic system is shutting down," Guterres reportedly warned.
Taliban fighters were accused of widespread evictions and revenge killings when they captured most of Afghanistan as local security troops and police collapsed and international backers fled the country.
Since then, the report alleges, the UN mission "continues to receive credible allegations of killings, enforced disappearances, and other violations" against former Afghan officials, security troops, and individuals who cooperated with the departed U.S.-led military contingent.
Such revenge attacks have taken place despite a Taliban declaration of a general amnesty, it notes.
Guterres cites credible reports that more than 100 individuals have been killed, in most cases by the Taliban or their allies, since August 15.
The UN secretary-general also says there are credible allegations of extrajudicial killings of at least 50 people suspected of being members of a local affiliate of the Islamic State (IS) militant group.