Hajji Saz Wali, the governor of Haska Meena District in the southern part of Nangarhar Province, said the victims included women and children, with eight of the dead from one family, and four others from a second. It was the second time since July 24 that an airstrike in that district killed civilians, according to Afghan officials.
The latest victims died Thursday afternoon when the vehicles they were traveling in were hit by American airstrikes believed to be targeting Islamic State militants in the area, Mr. Wali said. It is not known how many were wounded, he added.
A spokesman for the American military in Kabul said that those killed in the airstrikes had been seen loading weapons into a vehicle. “The strike was conducted in the middle of open terrain,” said the spokesman, Bob Purtiman. “There was zero chance of civilian casualties.”
Attaullah Khogyani, the spokesman for Nangarhar Province’s governor, confirmed that casualties had occurred but declined to give details.
Mohammada Khan, 42, a truck driver, said in a telephone interview that he had lost six members of his family — including two children and two women — in the airstrike, which hit a minibus in which they were fleeing.
“We got to the area of the bombing and put their body parts in a truck and brought them to Jalalabad city, where we buried them this morning,” he said. “There were no ISIS members in the area. It was not a valley or a mountainous area. It was a clear area, and they should understand that people in the vehicle are civilians, as the car was a civilian car.”
Mr. Khan added, “But it was God’s will, so we cannot say anything.”
On July 24, Afghan officials said, nine civilians were killed in an American airstrike on a prayer ceremony held in Haska Meena, near the border with Pakistan, by relatives of ISIS members who had been killed.
The American military asserted that that strike, too, targeted fighters. “This is the second false claim of civilian casualties in the same district within the last three weeks,” the military said in a news release.
As American airstrikes continue at a rapid pace, there have been a number of such episodes in recent months.
Claims of civilian deaths from airstrikes have occurred this year in Kunduz in the north and in Helmand Province in the south, often as a result of fighting in areas where it can be difficult to distinguish insurgents from civilians.
Haska Meena District, also known as Dih Bala District, is in a rugged area neighboring Achin District. Achin was long a stronghold of the Islamic State and was where the United States dropped the so-called mother of all bombs in April, the largest conventional bomb ever deployed, on a tunnel and bunker complex where insurgents had taken refuge.
That led Islamic State fighters to seek new refuge, including in the Tora Bora cave and tunnel complex in Nangarhar, which Osama bin Laden once used as a hide-out. The Islamic State fighters are believed to be relatively few, and in the Nangarhar area they fight against both the Afghan government and the more numerous Taliban insurgents.
The United States military has deployed Special Forces and airstrikes against Islamic State militants in Afghanistan and says it has killed dozens of the group’s leaders and hundreds of fighters this year.
Casualties among Afghan civilians, especially women and children, have risen to a record this year, according to a recent report from the United Nations. Most of those deaths have been attributed to insurgents, particularly through suicide bombings, rather than to airstrikes and other pro-government actions, the report said.