Three UN workers kidnapped in Kabul are probably not being held by Islamic militants, the Afghan authorities say.
The three were helping to organise the presidential poll on 9 October
"We think they are being held by some armed robbers who abducted them," an interior ministry spokesman said.
Annetta Flanigan from Northern Ireland, Shqipe Habibi from Kosovo and Filipino Angelito Nayan were abducted at gunpoint in Kabul on 28 October.
A group called the Army of Muslims repeated on Wednesday that it seized them. It has threatened to behead them.
The authorities said from the start they were keeping an open mind about who the kidnappers might be.
The BBC's Roland Buerk in Kabul says this is the first time the government has publicly said it doubts that militants are holding the hostages.
Interior Ministry spokesman Lutfullah Mashal said he did not believe the group - known in Afghanistan as Jaish-e-Muslimeen - had the resources to stage a kidnapping in Kabul.
"We don't think that Jaish has control over them - they are just a small group trying to make publicity," he told Reuters news agency.
He said the authorities believed the Army of Muslims had paid the real kidnappers for a video of the hostages in captivity.
But he had no details of any negotiations with those holding the trio, and said the authorities did not have a specific clue as to where they were being held.
"Our reports suggest that the hostages are still in or around Kabul.
"We are sure they are not far away. If Jaish militants were holding them, they would have released another video."
According to the Associated Press news agency, talks through intermediaries have been held up over ransom demands.
The Army of Muslims has set the release of jailed Taleban prisoners as a condition for freeing the hostages.
They were taken from a UN vehicle on a busy street in the capital after helping organise Afghanistan's first direct presidential elections, won by Hamid Karzai.
Security forces are monitoring traffic in the Kabul area
Spokesmen for the Taleban splinter group have reduced their demands as the days have passed. A series of deadlines have come and gone - without apparent incident.
But the group's leader, Akbar Agha, insisted on Wednesday his men were holding the three foreigners.
"These people are with Jaish," he told the Pakistan-based Afghan Islamic Press.
It has been suggested before that the kidnappers might not be militants, but the Kabul authorities have refused to speculate until now.
It remains unclear whether a criminal group would be less likely to harm the hostages.
The three have not been heard of since early last week when two were permitted to telephone home.