Taliban spokesman Zabihullah Mujahid denied that insurgents had been driven from Ghazni and said the Taliban destroyed a telecommunications tower on the city's outskirts during the initial assault, cutting off landline and cellphone links to the city, the AP reported.
While Afghanistan's Defense Ministry claimed that government forces would soon regain control of the city as "Taliban militants had been pushed back, " civilians at the scene say that fighting is ongoing.
At least 48 people have died after a suicide bomber targeted an education centre in a minority Shia area of western Kabul, in the latest assault in Afghanistan's war-weary capital.
The first, on Tuesday night, killed nine police and 35 soldiers at checkpoints in the north of the country, said officials in Baghlan province.
The Ghazni attack, one of the Taliban's most devastating in years, has clouded hopes for peace talks that had been prompted by an unprecedented ceasefire during the Eid celebration in June and a meeting last month between Taliban officials and a senior USA diplomat.
In Kabul, Nilab Mobarez, the secretary general of the Afghan Red Crescent Society, said her organisation was ready to go into Ghazni and help the wounded - both the civilians and the combatants.
The United States and North Atlantic Treaty Organisation have launched airstrikes and sent military advisers to aid Afghan forces as they fight for the city, just 120 kilometres from the Afghan capital with a population of some 270,000 people. He said seven attackers were killed and five were wounded during the battle, in which the Taliban used artillery and heavy weapons.
According to Zabul police the clash happened when a group of armed Taliban attacked police check posts on the highway near Qalat city of Zabul province.
Sibghatullah Sailab, deputy chairman for the provincial assembly, told Anadolu Agency the Afghan National Army base in Ghormach district was under the siege of the Taliban for the past two days, and the besieged soldiers finally surrendered late on Monday when no additional forces came for their rescue.
The Taliban have seized several districts across the country in recent years and carry out near-daily attacks targeting Afghan security forces.
"U.S. airpower has killed more than 220 Taliban since August 10", O'Donnell said.
But the Taliban may be less focused on gaining territory than it is on proving it is still in the game, for leverage.
Separately, six girls younger than 10 were killed when an unexploded mortar they picked up to play with suddenly exploded on Wednesday, officials in the eastern province of Laghman said.
He blamed insurgents, saying the rockets they fire at Afghan security forces often harm civilians. It is also plagued by roadside bombs planted by insurgents, which are usually intended for government officials or security forces, but often kill and maim civilians.