Two journalists and Afghans working with them have been arrested in the Afghan capital Kabul.
The UN Refugee Agency (UNHCR) said on Twitter on Friday.
The journalists were traveling on behalf of UNHCR.
"We are doing our utmost to resolve the situation in consultation with others," it said.
No further comment will be made "given the nature of the situation".
UNHCR did not release details about the identity of the journalists or the exact time of their arrest.
The militant Islamist Taliban, who have ruled Afghanistan since August, initially made no comment on the case.
Former Afghan Vice President Amrullah Saleh wrote on Twitter that the Taliban had arrested nine Westerners.
Those arrested include a former BBC journalist who now works for UNHCR and a restaurant owner.
The British newspaper "Daily Express" in turn reports that in the Afghan capital Kabul an employee of a Taliban secret service said that "several foreigners" had been arrested.
They are suspected of working for Western secret services, it said.