An Afghan official says the northern city of Kunduz has been captured by the Taliban after hours of clashes with security forces.
The capture of Kunduz by the Taliban is a major embarrassment for Afghan security forces who abandoned a provincial headquarters for the first time in 14 years.
Interior Ministry spokesman Sediq Sediqqi told the Associated Press news agency that "Kunduz city has collapsed into the hands of the Taliban."
The Taliban said earlier that it had seized the provincial government headquarters in Kunduz and were moving towards the main airport where some government officials had fled.
Militants raised the white Taliban banner over the central city square and freed hundreds of fellow militants from the local jail.
Officials said Afghan special forces were on their way to Kunduz to retake the city, which has a population of around 300,000 people.
Dozens of Afghan special forces have already been flown into Kunduz airport on a C-130 aircraft and were preparing to launch a counter-attack, an Afghan official told the Reuters news agency.
“Heavy fighting continues in the city center,” provincial deputy governor Hamdulla Daneshi told RFE/RL’s Radio Free Afghanistan earlier on September 28. “The city is divided in two parts and it’s turned completely to a warzone.”
"Security forces in Kunduz were prepared for an attack but not one of this size, and not one that was coordinated in 10 different locations at the same time," Interior Ministry spokesman Sediq Sediqqi said.
The United Nations Assistance Mission in Afghanistan evacuated its Kunduz compound on September 28, soon after the assault began.
"They've been relocated within Afghanistan," said UN spokesman Dominic Medley, declining to say where or how many staff were evacuated.
The once-quiet north of Afghanistan has seen escalating violence in recent years.
Kunduz city was the center of fierce fighting in April as the Taliban sought to gain territory after NATO ended its combat mission in Afghanistan last December and pulled out the bulk of its troops.
Kunduz Province contains major roads that connect central and northern Afghanistan, including a road to the capital, Kabul.
The attack comes a day after a suicide attack at a game of cricket in the eastern province of Paktika killed at least nine people and wounded more than 30.
There was no immediate claim of responsibility.
The explosion was caused by a motorcycle bomb, local officials said, and probably targeted local government officials watching the match.
A similar attack last year at a volleyball match killed at least 50 people in the same province.
Earlier on September 27, Afghan officials said Islamic State (IS) militants attacked checkpoints in Nangarhar Province, killing three police officers.
Provincial government spokesman Ahmad Zia Abdulzai said another eight policemen were wounded in the attack in the Achin district, bordering Pakistan.
He also said Afghan air strikes launched after the early morning attack killed 60 IS militants.
A UN report published on September 25 warned that IS was making inroads in Afghanistan, winning over a growing number of sympathizers and recruiting followers in 25 of the country's 34 provinces.