It has been reported that Northern Alliance fighters have begun attacking Kunduz.
Reporting from the nearby city of Taloqan, Russia's Interfax news agency quoted the Alliance's General Daoud Husaini as saying that 5,000 of his forces had begun moving on Kunduz at noon (0730 GMT). There was no independent confirmation of the report.
General Husaini, commander of the Alliance's eastern front, said about 1,200 Taliban fighters had surrendered at dawn outside the city and given up their weapons after completing negotiations with a Taliban commander.
Those who surrendered included around 600 foreign fighters, he said, adding that further talks would take place later in the day to secure the bloodless surrender of more fighters.
It is not known exactly how many of the estimated 15,000 Taliban soliders holed up in the city intend to give themselves up.
Most of the Taliban's remaining forces are massed in Kandahar. However, an estimated 15,000 Taliban fighters, including several thousand Arabs, Pakistanis and Chechens linked to al Qaeda, are besieged in Kunduz. They have been encircled by Northern Alliance forces for more than a week.
The al Qaeda soldiers have vowed to fight to the death, fearing torture at the hands of the Northern Alliance.
Last night the Northern Alliance suspended their assault to give the Taliban one more day to surrender, but vowed to press on with their attacks if no deal was reached today.
The discovery of up to 600 bodies in Mazar-i-Sharif, and Washington's determination that the defenders of Kunduz should not escape, have fueled fears of a massacre if the Alliance captures Kunduz.
Northern Alliance commanders say the foreign fighters have executed hundreds of Afghans who wanted to surrender.
The US military's Central Command said a 15,000-pound BLU-82 bomb, called a "Daisy Cutter," was dropped near Kandahar on Wednesday. It was only the third time the weapon - which produces a blast like that of a small nuclear bomb and devastates an area 600 yards wide - had been used in Afghanistan.
Conflicting reports have also emerged on the whereabouts of the Taliban's spiritual leader, Mullah Mohammed Omar, bin Laden's main Afghan protector.
Taliban official Mullah Sayed Haqqani said Mullah Omar had left the city, but the Pakistan-based Afghan Islamic Press quoted Mullah Omar's spokesman, Tayab Agha, as saying, "He is still in Kandahar and still has contact with his fighters."