A city in southwestern Afghanistan has become the country's first provincial capital to fall to the Taliban in recent years, officials told the BBC.
Two sources said the insurgents had captured Zaranj, in Nimroz province, on Friday afternoon. It has not been officially confirmed.
They have taken swathes of countryside and are now targeting key cities.
Other provincial capitals under pressure include Herat in the west and Lashkar Gah in the south.
Zaranj is a major trading hub near the border with Iran. After capturing surrounding districts, the militants had been making a sustained attempt to capture the city.
A government source told the BBC that fighting was still happening around the National Directorate of Security office.
An unnamed spokesperson for Nimroz's police told Reuters news agency that the Taliban had been able to capture the city because of a lack of reinforcements from the government.