The Afghan Taliban seized a strategic district in the northeastern Kunduz province on August 20, forcing troops to retreat to the provincial capital, which was briefly overrun by insurgents last year.
"The Taliban attacked the district from different positions and we resisted for hours but we received no support. The district fell to the Taliban," said Hayatullah Amiri, the chief of the Khanabad district.
The militants captured Khanabad in the early morning and there was heavy fighting taking place in several other districts, officials said.
Taliban spokesman Zabihullah Mujahid said the Taliban took over the district along with military vehicles and weapons.
Mohammad Yusouf Ayubi, head of the Kunduz provincial council, said hundreds of civilians have escaped the fighting, warning that "if the central government does not pay attention to Kunduz, the Taliban will overrun Kunduz city as they did last year."
Just five days earlier, the Taliban captured a district in neighboring Baghlan province, taking government forces' ammunition and vehicles.
Afghan security forces are fighting the Taliban in at least 15 out of 34 provinces, according to the Defense Ministry.
Based on reporting by AP and Reuters