"The Americans told people around the base to leave [the area], and they left. About 700 metres from the district office they bombed," he said.
Nuristani said that although a mistake by US forces may have caused the deaths, the incident was "inexcusable because [the US] knew that these civilians were leaving the area."
"I think the president, the whole cabinet and the people of Afghanistan are getting angry, and that is not helping our cause, nor the Americans or Nato. It is helping the Taliban, not us," he said.
A spokesman for the US-led coalition insisted that fighters who had attacked a military base earlier were targeted.
The helicopters tracked them down and destroyed the vehicles they were traveling in, First Lieutenant Nathan Perry said.
"These were combatants. These were people who were firing on us," Perry said.
"We have no reports of non-combatant injuries," he said, giving no information on the casualties in the vehicles.
Hamid Karzai, Afghanistan's president, ordered an investigation into the air raid in the remote district of Waygal near the border with Pakistan and said he was "deeply saddened" by the deaths.
In a separate incident, an Afghan parliament member was killed in a gun attack in the southern province of Kandahar, a district governor said.
"Habibullah Jan was shot dead by unknown gunmen while going home on Friday evening," Niaz Mohammad Sarhadi, governor of Zharai district in Kandahar province said.
Jan was killed hours after he had visited an Afghan army compound in Zharai.
Zharai is a particularly dangerous part of Kandahar where Canadian forces from the Nato alliance have battled fighters loyal to the Taliban over the last two years.
Yousuf Ahmadi, a spokesman for the Taliban, denied that their fighters had any involvement in the killing.
"This is not our work," Ahmadi, speaking from an unknown location, told AFP by telephone on Saturday.
Jan was a military commander in the area before he become a member of parliament.
Meanwhile on Saturday, 10 Taliban fighters were killed in Helmand province when a roadside bomb they were planting detonated prematurely, Mohammad Hussein Andiwal, a police chief, said.