A man and a woman who allegedly had an adulterous affair have been stoned and killed in the northern Afghan province of Kunduz.
The punishment happened in a crowded bazaar on Sunday in the Taliban-controlled village of Mullah Quli.
The Taliban have not commented on the public killing, but it was confirmed by local officials and witnesses.
This month the Taliban also reportedly flogged and killed a pregnant widow in western Baghdis province.
A spokesman for Afghan President Hamid Karzai, Waheed Omar, said if the incident was confirmed it would be condemned in the strongest terms by the government.
"Even in Islam this [stoning] has to be done through proper judicial systems," he said.
"The Taliban do not represent the country, they do not represent the Afghan judiciary, and they have no right to punish anyone even if it is for the right cause, which in this case it is not."
Stoned and shot
Mohammad Ayub, governor of Imam Sahib district in Kunduz, told the BBC that the Taliban had brought the man and woman to the local bazaar, where they stoned them before a large crowd.
The Taliban asked the villagers to attend the stoning through an announcement on loudspeakers in the mosque, two witnesses from Mullah Quli told the BBC.
"There was a big crowd of people," one said.
"The Taliban made the women wear black clothes and the men were made to stand. The Taliban started throwing stones. We were also asked to throw stones. After a while, the Taliban left. The woman was dead but the man was still alive.
"Some Taliban then came and shot him three times. The Taliban warned villagers if anyone does anything un-Islamic, this will be their fate.''
According to news agency AFP, the woman was 23 years old and the man was 28.
A local tribal elder told the BBC that the couple had eloped and that the woman had been engaged, while the man was already married.
A jirga (tribal council) met and decided that the couple could come back to the village if the man paid compensation.
"The man returned after he was assured that he wouldn't be harmed," said the elder. "The Taliban arrested them as soon as they came back.''
A Kunduz-based official with the Afghan intelligence agency, the NDS, confirmed the account, saying the Taliban wanted "to create a climate of fear."
Taliban 'free rein'
The BBC's Bilal Sarwary in Kabul says Taliban and al-Qaeda militants have been tightening their grip in several parts of Kunduz province where the central government has little control.
The Taliban operate a shadow government consisting of judges, tax collectors, district governors and commanders, in these areas, he adds.
Until now, the strength of the Taliban in the northern part of Kunduz had not been realised, Amnesty International's Asia Pacific director Sam Zarifi told BBC World Service.
The Taliban and other insurgent groups began systematically taking over Kunduz in early 2009, he said, reaching out in part to the large Pashtun population but also bringing in their own people.
"Meanwhile, the German contingent, the military contingent that was up there, effectively had a non-confrontational stance and so the Taliban had the free reign of the place," Mr Zarifi said.
He said the Taliban were seeking to create and exploit a power vacuum, and he urged the government and the ostensibly pro-government Council of Ulema (religious scholars) to take a stronger stance against extremism.
"It's particularly worrying because the Council of Ulema just last week asked for stricter interpretation and implementation of Sharia laws, including physical punishment, so overall this is a very worrying development," the Amnesty International expert said.