Two U.S. troops were killed and two others wounded Thursday during an operation alongside Afghan forces in Kunduz province, the U.S.-led military coalition said in a statement.

The statement released by the coalition said the U.S. troops came under fire “during a train, advise and assist mission with our Afghan partners to clear a Taliban position and disrupt the group’s operations.”

"Today's loss is heartbreaking" - Gen. Nicholson, RS COM, on two U.S. casualties https://t.co/mRWacIbpv1 — Resolute Support (@ResoluteSupport) November 3, 2016

Gen. John W. Nicholson, commander of America’s forces in Afghanistan, expressed his condolences to the families and friends of the slain troops, and said the two wounded soldiers were “receiving the best medical care possible and we are keeping them and their families in our thoughts today, as well.”

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So far 10 U.S. service members have died in Afghanistan this year. One American civilian was also killed in an attack in Kabul in October.

The American military presence in Afghanistan has been scaled down since the U.S.-led invasion to oust the Taliban government in October 2001, but approximately 10,000 U.S. troops remain in the country as part of NATO’s “Resolute Support” mission.

The NATO combat mission in Afghanistan officially ended in 2014, when responsibility for the nation’s security was handed over to domestic forces.

Police and officials in the Kunduz Governor’s office told CBS News the Thursday operation was conducted by Afghan special forces trying to kill or capture two senior Taliban commanders in the Bous Kanahari area, about 10 miles outside the provincial capital of Kunduz city.

Governor’s spokesman Sayed Mahmoud Danish said 26 Taliban fighters, including the two senior Taliban commanders targeted in the operation, were killed in the fighting and 17 others wounded. Four Afghan soldiers were also killed and six wounded in the operation, he said.

Relatives and members of civilians sit next to the dead bodies of children who were killed during clashes between U.S.-backed Afghan security forces and the Taliban in Kunduz, Afghanistan, Nov. 3, 2016. REUTERS

He said 30 civilians, including women and children, were also killed during the battle, and as many more wounded. Danish said the civilian deaths may have been caused by Afghan aircraft called in to support ground troops, and an investigation had been launched into the casualties.

Mehfuzullah Akbari, a spokesman for Kunduz’ chief of police, told CBS News the airstrikes were conducted by U.S.-led coalition aircraft after the ground forces became surrounded by Taliban fighters and requested help.

To clarify, US forces conducted strikes in #Kunduz to defend friendly forces. All civilian casualty claims will be investigated. — Resolute Support (@ResoluteSupport) November 3, 2016

The U.S. military did not immediately make its own comment on the reports of civilian deaths or airstrikes, but NATO confirmed in a tweet that U.S. aircraft had conducted strikes in support of the Kunduz operation, adding that “all civilian casualty claims will be investigated.”

Taliban fighters briefly overran the city of Kunduz, the provincial capital with the same name, in early October, a show of strength by the insurgents that also highlighted the troubles facing local Afghan forces some 15 years after the U.S.-led invasion of the country. The Taliban captured and held parts of Kunduz a year earlier as well before the city was fully liberated weeks later with the help of U.S. airstrikes.

Those 2015 airstrikes also saw a U.S. Air Force special operations AC-130 gunship attack a Kunduz hospital run by the medical charity Doctors Without Borders, killing 42 people. Sixteen U.S. military personnel, including a two-star general, later were disciplined for what American officials described as mistakes that led the strike. Doctors Without Borders has called the attack a war crime and demanded an independent investigation.