By Andrew North
BBC correspondent in Kabul
A regional militia commander in the northern Afghan city of Mazar-e-Sharif has demanded the police chief appointed by central government leave the area.
Atta Mohammad's troops surrounded the police chief's house last week
Atta Mohammad set no deadline for police general Akram Khakrezwal to go - but said he must leave by land or air.
It is the latest development in a stand-off between the militia leader and the police chief.
President Karzai has warned that private militias pose a greater threat to Afghan stability than the Taleban.
In a New York Times interview, he acknowledged a nationwide disarmament programme had so far failed to reduce the power of these militias.
The row in Mazar-e-Sharif blew up after the police chief's men made a large drug seizure 10 days ago and then accused Atta Mohammad of being involved in the illegal trade.
Despite the fact that President Karzai appointed the police chief, many expect the central government team that has been mediating in the dispute to recommend his replacement to reduce tension there.
But the militia leader is effectively pre-empting that decision.
In a way he is also providing an example of the problems Mr Karzai was talking about in his New York Times interview.
Afghanistan's progress has been held back by private militias, he said in a generally downbeat interview, and could not be tolerated.
One reason parliamentary and provincial polls have been postponed until next year is the slow pace of disarming the militias.
So far only about a fifth have been demobilised - well short of the target.
Yet some believe President Karzai has been too ready to do deals with militia commanders.
In his interview he defended his approach.
But with Nato countries so far failing to live up to commitments to provide more troops to boost security in the provinces, some feel he has had no choice to try to maintain some kind of temporary stability.