The Taliban claim 13 civilians have died in the latest attacks near Kandahar.
It comes after a senior defence official said gunships, which are used to carry ground troops, are involved in special operations in Afghanistan.
The AC-130 turboprop plane was used by American forces trained for small-unit operations in hostile countries.
As well as Kandahar, the latest air strikes have targeted military bases in Kabul and the northern city of Mazar-e-Sharif.
Abdul Himat, a Taliban Information Ministry official, claimed 13 civilians died in the attacks at Kandahar. The claim has not been confirmed.
There has been no confirmation on whether the gunship's deployment means special forces have entered the battle on the ground.
The Afghan opposition, Northern Alliance, says its troops have advanced to within three miles of the airport at Mazar-e-Sharif.
In Washington, a defence official says the attack was led by a AC-130, marking the first acknowledged use of special-forces aircraft.
Defence Secretary Donald Rumsfeld says US air strikes could next start targeting Taliban front-line positions facing Afghan opposition fighters in the northeast of the country.