The Taliban have seized Jalalabad, the capital of the eastern province of Nangarhar, on Sunday morning, according to local officials. The city was reportedly given up without resistance.
Afghan lawmaker Abrarullah Murad told AP news agency that elders in the city negotiated with the Taliban for the government to leave.
"We woke up this morning to the Taliban white flags all over the city. They entered without fighting," Jalalabad resident Ahmad Wali told news agency AFP.
Photos on social media show members of the Taliban sitting in the governor's office in Jalalabad.
Jalalabad had a population of around 356,000 people as of 2014. Jalalabad is around 65 kilometers (40 miles) from the Pakistani Torkham border crossing, making it a center for international trade.
Kabul is now the only major city in Afghanistan controlled by the government. Jalalabad's capture effectively cuts off Kabul to the east.
Former Afghan ambassador: Ghani's resignation could help avert Kabul attack
Omar Samad, a former Afghan ambassador to France and Canada, told DW Saturday that President Ashraf Ghani's resignation could lead to an interim government, which he said could possibly avert a Taliban attack on Kabul.
"Apparently, the president is not still ready to step down in order to pave the way for an interim government, a transitional period for Afghanistan that would probably save Kabul from any type of attack," Samad said.
"The Taliban don't seem to want to attack, from what we hear ... they might use other means, other cities fell with almost no shooting going on, very few casualties. Kabul is going to be different," he added.
"The international community needs to still be committed to Afghanistan, especially on the humanitarian side, from now on," he said of the global response to the situation.
Afghan soldiers cross into Uzbekistan
Uzbekistan says it has detained 84 Afghan soldiers who crossed its border on Saturday.
The Tashkent government said another group of troops are waiting near a checkpoint on the Afghan side of the frontier between the two countries.
Officials are providing humanitarian aid to the soldiers, who are positioned close to the Termez-Khairaton bridge.
Members of Afghanistan's military escaped into Uzbekistan and Tajikistan last month when retreating from a Taliban advance.
Talks are being held between both countries to return the 84 troops to Afghanistan.
