KABUL, Afghanistan (AP) - A fierce battle between U.S.-backed Afghan forces and Taliban militants in a remote corner of eastern Afghanistan left nearly 20 people dead, including 11 Afghan children killed in an airstrike and an American civilian adviser, officials said Sunday.
The fighting along a main infiltration route from Pakistan on Saturday was indicative of a surge in hostilities as Afghanistan's spring fighting season gets underway.
The U.S.-led coalition confirmed that it launched airstrikes in Kunar province where the deaths occurred, stressing that they were requested by international forces. The coalition said it was assessing the incident, but could not confirm that civilians were killed.
The battle unfolded on Saturday, the same day that a total of six Americans, including three U.S. soldiers, died in violent attacks.
The death of Afghan civilians caught in the crossfire has been a major point of contention between international forces and the Afghan government.
Afghan officials said the airstrike occurred after a joint U.S.-Afghan force faced hours of heavy gunfire from militants. The joint force was conducting an operation targeting a senior Taliban leader that began around midnight Friday in the Shultan area of Kunar's Shigal district.
"In the morning after sunrise, planes appeared in the sky and airstrikes started," an Afghan official said. The fighting didn't end until the evening.
"I don't think that they knew that all these children and women were in the house because they were under attack from the house and they were shooting at the house," he said.
The official said the main Taliban suspect was in the house that was hit and was killed along with a woman and the children, ages 1 to 12, who were members of the suspect's family.
A provincial spokesman said 10 children and one woman were killed.
and five women, who also were in the house, were wounded.
Karzai's office later said 11 people were killed - all of them children - and six women were wounded.
"While the president strongly condemns the Taliban act of using people and their houses as shields, he also strongly condemns any operation on populated areas that results in civilian casualties," his office said in a statement.
An airstrike in the same district in Kunar that killed 10 civilians in mid-February prompted Karzai to ban his forces from requesting airstrikes.
Afghanistan's Interior Ministry said six Taliban militants were killed in the operation in Sano Dara Sheltan village, including two senior commanders identified as Ali Khan and Gul Raof, the main planner and organizer of attacks in the area.
The U.S.-led coalition said it provided fire support from the air, killing several insurgents.
"The air support was called in by coalition forces, not Afghan security forces, and was used to engage insurgent forces in areas away from structures, according to our reporting," coalition spokesman Maj. Adam Wojack said in a statement.
He said the coalition takes all reports of civilian casualties seriously, and was currently assessing the incident.
Afghan forces have been increasingly taking the lead in combat operations as international forces move to complete their withdrawal by the end of 2014. But U.S. and other foreign troops still face dangers as they try to clear areas of insurgents and prepare the Afghans to take control.
Gen. Martin Dempsey, the top U.S. military officer, told the AP in an interview on Sunday in Afghanistan that he was cautiously optimistic about the final stage of handing off security responsibility to Afghan forces.
Asked if he thought that some parts of Afghanistan will be contested by the Taliban in 2015, Dempsey replied, "Yes, of