U.S. officials are bristling after Afghan authorities said Monday that American forces probably never came under fire during a firefight at a U.S.-controlled base in Kandahar last week.

Two U.S. troops were wounded in the attack on Wednesday, when witnesses said attackers came within 30 feet of foxholes on the perimeter of the base.

Afghan provincial authorities suggested the rounds were fired by mistake and that may have caused U.S. soldiers to fire back.

A U.S. spokesman at the base called that assertion "beyond belief."

"The general impression is it was a mistake, a burst of fire," said Yusuf Pashtun, spokesman for Kandahar Gov. Gul Agha.

"We are 90 to 95 percent sure the incident was not an attack on Americans. ... It was a mistake," said Maj. Naik Mohammed, Afghan commander in this southern city.

U.S. soldiers on duty at the time along the base's miles-long boundaries were adamant they came under incoming fire.

"I don't know if the gunmen had night vision equipment, but if they didn't they must have had some hellified eyes that could see in the dark — their fire was that intense, that accurate," Lt. Darren McDonough, who was grazed in the neck by a bullet during the firefight, told The Associated Press last week.

He pinched his fingers together to show the nearness of the bullets.

"They're not really coming under attack," said Ahmed Wali Karzai, a brother of Afghan interim Prime Minister Hamid Karzai and a member of Kandahar's local council who is believed to work closely with covert American forces in Afghanistan's south.

Maj. A.C. Roper, a spokesman for the 101st Airborne Division at Kandahar airport, rejected the Afghans' version of events.

"Two of our soldiers suffered minor wounds and give accounts of rounds ricocheting off their fighting positions. To suggest this incident didn't occur as stated is inconsistent with the facts and simply beyond belief," Roper said.

Spc. Timothy Bates said enemy rounds began striking one of the base's bunkers and that the U.S. soldiers returned fire with a heavy machine gun.

"Mostly we were just angry when they fired at us," he said. "At one point I began to feel a burning sensation in my hand and when I held the pistol grip of my weapon it felt sticky with my own blood and I realized that I'd been hit in the hand."

Attacking the base "would mean going through mine fields. How can you?" asked Karzai, speaking at his home in Kandahar.

The airport itself was targeted many times during Afghanistan's two decades of war. Russians who held the airport in the 1980s ringed it with three circles of mines to ward off intruders, at times stacking as many as six mines on top of each other.

Intruders allegedly tested the base's defenses again the next night, Thursday, when soldiers spotted a vehicle with three passengers about a mile southwest of the base. U.S. troops responded by firing flares, which sparked a fire.

U.S. military spokesmen have cited "pockets of resistance" by Taliban or Al Qaeda in the attacks. While many Taliban supporters remain in the south, no Al Qaeda have been seen in the area around the airport, Afghan officials said.

"Nobody has the power to attack Americans in this city," said Mohammed.

The base at Kandahar holds thousands of troops of the U.S.-led coalition, and is the U.S. military's largest post in Afghanistan.

The Associated Press contributed to this report.