Afghan security forces have captured fugitive Taleban leader Mullah Omar's former security chief, officials say.
A rare picture of Mullah Omar
Mullah Naqibullah Toor is reported to have been picked up with another Taleban commander on Monday in the southern city of Kandahar.
Provincial government spokesman Khalid Pashtun confirmed the arrests.
Officials hope documents found on the men could help find Mullah Omar or Osama Bin Laden, but some observers doubt the significance of the arrests.
They point out that there has been no independent confirmation of the identities of the two men reportedly held.
The BBC's Rahimullah Yusufzai, a long-time watcher of the Taleban, says the two men's importance is not clear, despite the official claims.
A spokesman for the Taleban, meanwhile, called the BBC and denied the two named men had been arrested.
Mullah Naqibullah Toor was unarmed when he was arrested late on Monday after a tip-off, Kandahar officials say.
He headed Mullah Omar's household security when the Taleban controlled Afghanistan.
Afghan officials accuse him of a string of attacks, and say his arrest is highly significant.
"It will definitely help to reduce bomb attacks and insurgency in
Kandahar because he was the main person organising these kind of attacks," Kandahar police chief Khan Mohammed told AFP news agency.
Officials say Mullah Naqibullah Toor was seized along with a second man, Mullah Qayyum Angar, an alleged Taleban commander accused of involvement in recent violence in the province.
The American military, which has many troops in Kandahar, said it had no information on the arrests, but was checking the reports.
US forces recently offered an amnesty to all but the most senior Taleban leaders, but it is not yet clear if the initiative is working.
The BBC's Andrew North in Kabul says if the importance of these arrests is confirmed, it would be a boost for the US and Afghan authorities.
US-led forces have been hunting militants since 2001
But he says there have been instances in the past of both claiming to have arrested or killed Taleban leaders which have turned out to be incorrect.
The Taleban were ousted in late 2001 when US forces invaded Afghanistan following attacks on the World Trade Centre in New York and the Pentagon in Washington.
The Taleban had given sanctuary to Osama Bin Laden and members of his al-Qaeda network, who are accused of carrying out the attacks.