Taliban insurgents detained veteran militia commander Mohammad Ismail Khan on Friday after they seized the western city of Herat, a provincial council member said.
Mr Khan, 75, who has been leading fighters against the Taliban in recent weeks, was handed over to the insurgents along with the provincial governor and security officials under a pact, provincial council member Ghulam Habib Hashimi told Reuters.
“The Taliban agreed that they will not pose any threat or harm to the government officials who surrendered,” Mr Hashimi said.
Mr Khan is one of Afghanistan's most prominent warlords. Known as the Lion of Herat, he battled Soviet occupiers in the 1980s and was a key member of the Northern Alliance whose US-backed forces toppled the Taliban in 2001.
Taliban spokesman Zabihullah Mujahid confirmed that Mr Khan had been detained.
Taliban insurgents tightened their grip on Afghanistan on Friday, wresting control of its second and third biggest cities while western embassies prepared to send in troops to help move staff from the capital, Kabul.
The capture of Kandahar in the south, the second-biggest city, and Herat in the west, after days of fighting are a devastating setback for the government as the deadly Taliban insurgency turns into a rout of the security forces.
"The city looks like a front line, a ghost town," provincial council member Ghulam Habib Hashimi told Reuters from Herat, a city of about 600,000 people near the border with Iran.
"Families have either left or are hiding in their homes."