Mr Khosti did not identify the victims, but sources in Mazar-i-Sharif told the AFP news agency that one of the dead was a women’s rights activist and university lecturer, Frozan Safi.
Three sources in Mazar-i-Sharif told AFP that they had heard the women received a call that they thought was an invitation to join an evacuation flight and were picked up by a car, only to be found dead later.
“I knew one of those women, Frozan Safi,” a female employee of an international organisation told AFP, on condition of anonymity. “She was also a women’s activist, really well known in the city.”
The source said that three weeks ago she had herself received a call from someone pretending to offer assistance in her efforts to get to safety abroad.
“He knew all information about me, asked me to send my documents, wanted me to fill a questionnaire, pretending to be an official of my office in charge of giving info to the US for my evacuation,” she said.
After becoming suspicious she blocked the caller, and is now living in fear. She was shocked when she heard about the killings.
“I was already scared,” she said. “My mental health is not good nowadays. I am always afraid that someone might come to my door, take me somewhere and shoot me.”
The Taliban, who seized power in Afghanistan in August after a 20-year war against the former US-backed government, are a deeply conservative Islamist movement.
Under their last period of rule, women were banned from public life and since the group’s return to government many rights activists have fled the country.
Some women who remained have held street protests in Kabul demanding that their rights be respected and that girls be allowed to attend public high schools.
Taliban fighters have broken up some of the protests, and the government has threatened to arrest any journalists covering unauthorised gatherings.
But the movement’s leaders have insisted that their fighters are not authorised to kill activists, and have promised that any who do will be punished.