Foreign officials in Afghanistan are in urgent discussions with the Afghan government over two diplomats who have been ordered to leave the country.
The men, based in Kabul, are accused of posing a threat to national security.
One is a high-ranking United Nations employee, the other was acting head of the EU mission in Afghanistan.
The expulsion order follows speculation that the men - one British, one Irish - had held talks with the Taleban in Helmand province in the south.
The Afghan government has given the pair 48 hours to leave.
But a spokesman for the UN in Afghanistan, Aleem Siddique, said the affair was a misunderstanding, which he hoped would be resolved.
Mr Siddique denied that the diplomats had been talking to Taleban militants.
He said they had been discussing the Afghan situation with all people on the ground to help the country's stability.
"We are currently trying to clarify the situation with the Afghan authorities, and we are hopeful that our staff member and the UN can continue with the essential work that is required to deliver peace, stability and progress to the people of Helmand province," Mr Siddique said.
Homayun Hamidzada, spokesman for Afghan President Hamid Karzai, said: "The foreign nationals have been declared persona non grata and their Afghan colleagues have been arrested and are being investigated."
He said they had been "involved in some activities that were not their jobs".
'Storm in a teacup'
Alastair Leithead, BBC correspondent in Kabul, says the two spoke to a lot of different groups across the country.
He says their role was to try to find out what was happening "on the ground" with tribal elders, government representatives and non-government representatives.
Officials have stressed these discussions should not be interpreted as support for the Taleban.
Our correspondent says people are describing the situation as a storm in a teacup which has been taken much further than expected.
A former Afghan Interior Minister, Ali Jalali, told the BBC that similar misunderstandings had happened before:
"Unco-ordinated moves by certain elements of the international community have caused problems in the past, which the Afghan government sees as undermining its sovereignty," he said.
"This issue is not going to be resolved unless the Afghan government and its international partners come up with a unified strategy and a shared vision," he added.
Helmand province, where the two diplomats held talks with tribal leaders, is the heart of Afghanistan's drug-producing region, and the EU and UN have been playing a major role in the eradication programme.
Analysts say the poppy industry has been a primary reason for the Taleban's resurgence in the south of the country.
The row comes as a British newspaper, the Daily Telegraph, reports that members of Britain's secret intelligence service, MI6, held meetings during the summer with senior Taleban members in Afghanistan.
If true, this could prove embarrassing for British Prime Minister Gordon Brown, who just weeks ago told MPs that there would be no negotiations with members of the Taleban.