Abdul Hai Mutamean, a Taliban spokesman, said that the Taliban had full control of the airport and other installations in Shiberghan, the stronghold of the Uzbek warlord, General Abdur Rashimd Dostum.
He said the Taliban also seized a large amount of ammunition, tanks and military equipment after the opposition forces retreated in haste.
Shiberghan is the latest Taliban victory in the north-west, that was under the general control of the opposition.
On Saturday, the militia gained control of Andkhui, a district of Faryab province after opposition fighters had fled, leaving a large cache of ammunition. A day before, the Taliban captured Daultabad district.
The Taliban controls more than two-thirds of Afghanistan and is trying to capture the rest from opposition forces. It aims to enforce strict Islamic Sharia law nationwide.
Azizullah Shafaq, a spokesman for the Shia Muslim Hezb-i-Wahdat, a member of opposition alliance, said the opposition forces retreated from Shiberghan, some 120 km (75 miles) to the west of the Balkh province capital of Mazar- i-Sharif, the only major city outside Taliban control.
The Taliban capture of Shiberghan has cut off a supply route for the opposition from neighbouring Turkmenistan. The town had a functioning airport with scores of jet fighter and transport planes.
The Taliban said that, while retreating, the opposition forces set fire to most of the planes. But Mr Shafaq said most of the aircraft were taken to Mazar-i-Sharif.Reuse content