The Taliban in Afghanistan has sought to reassure the international community but UN rights officials are fearful for the safety of thousands of Afghans who have worked on human rights issues as well as women and girls.
The United Nations has called on countries to ban all forced returns of Afghans to their conflict-torn nation, following the Taliban's swift military takeover that triggered panic in Kabul.
The UN refugee agency said it had released a "non-return advisory" for Afghanistan, insisting no Afghan nationals should be forced to return, including asylum seekers who have had their claims rejected.
"In the wake of the rapid deterioration in the security and human rights situation in large parts of the country and the unfolding humanitarian emergency, UNHCR calls on states to halt forcible returns of Afghan nationals who have previously been determined not to be in need of international protection," agency spokeswoman Shabia Mantoo told reporters in Geneva.
She welcomed the fact that a number of European countries had halted all forced returns to Afghanistan, and voiced hope that others would quickly follow suit.
Tens of thousands of people have tried to flee Afghanistan to escape the hardline rule expected under the Taliban, or fearing direct retribution for siding with the US-backed government that ruled for the past two decades.
Even before the chaos in recent days, Mantoo said more than 550,000 Afghans have been internally displaced as a result of conflict and insecurity since the beginning of the year.
"While civilians have so far only fled sporadically in fewer numbers to countries neighbouring Afghanistan, the situation continues to evolve rapidly," she said.
The Taliban has sought to reassure the international community that Afghans should not fear them but the UN voiced deep concern at the risk of rights violations against civilians, in particular women and girls and those seen as having been associated with the Afghan government, international organisations or military forces.
"We call on the international community to extend all possible support to those who may be at imminent risk," UN rights office spokesperson Rupert Colville told reporters.
He also urged the Taliban to honour the promises made to be inclusive and to allow women and girls to work and go to school.
"Whether or not they are honoured or broken will be closely scrutinised," he said, calling on the Taliban "to demonstrate through their actions, not just their words, that the fears for the safety of so many people from so many different walks of life are addressed."
Women in several cities have already reported being removed from their workplace by the Taliban and asked to send a "male relative" as a replacement.
Thousands of Afghan rights workers at risk
Top United Nations human rights official expressed fear on Tuesday for the safety of thousands of Afghans who have worked on human rights issues, while the UN refugee agency called for an end to the forced deportation of Afghan asylum seekers.
"We are particularly concerned about the safety of the thousands of Afghans who have been working to promote human rights across the country, and have helped improve the lives of millions," a spokesperson for Michelle Bachelet, the United Nations High Commissioner for Human Rights (UNHCR ), told a UN briefing.
New Taliban health commissioner
The UN children's agency UNICEF said staff at its 13 field offices across the country had been in contact with NGO coordinators appointed by the Taliban as they had taken over cities, as well as a new Taliban health commissioner.
"We are slightly optimistic because he told women health workers to report to their offices," UNICEF's field operation and emergency chief Mustapha Ben Messaoud told the Geneva press conference via video link from Kabul.
But the agency lamented the heavy toll the conflict has already taken, saying more than 550 children had been killed and 1,400 injured in Afghanistan since the start of the year.
More than 18 million people, including nearly 10 million children, need humanitarian assistance, and half of all children under five in the country could be severely malnourished by the end of the year, unless urgent action is taken, UNICEF warned.
"Afghanistan has for many years been one of the worst places on earth to be a child," Ben Messaoud said.
"In the past few weeks it has got worse."