KABUL, Afghanistan (AP) — Two U.S. service members were killed on Thursday battling Taliban insurgents in northern Afghanistan alongside local troops, NATO said, rare combat deaths for American forces who largely handed over securing the war-torn nation to Afghan troops some two years ago. 
  
 Kunduz officials later said they were investigating claims that local civilians also were killed in the fighting, possibly in a retaliatory airstrike. 
  
 NATO described the Americans killed and two other Americans wounded in the assault as being part of "a train, advise and assist mission" in Afghanistan's Kunduz province. 
  
 "Today's loss is heartbreaking and we offer our deepest condolences to the families and friends of our service members who lost their lives today," Gen. John W. Nicholson, commander of U.S. Forces-Afghanistan, said in a statement. 
  
 NATO declined to identify those killed, pending notification of the next of kin. NATO and the Pentagon did not immediately respond to a request for comment from The Associated Press to further clarify the American troops' mission in the area. 
  
 Kunduz official Mohammad Yousf Ayoubi and parliament member Malim Chari both later told the AP that civilians were killed in the fighting, though details were few. NATO and the Pentagon also did not immediately respond to questions about the claim. 
  
 A Taliban statement also said there were civilian casualties while claiming its fighters killed 16 U.S. troops. The insurgents often exaggerate their battlefield successes. 
  
 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 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. 
  
 NATO's combat operations ended in Afghanistan at the end of 2014, a move that put Afghan forces in charge of the country's security. Since then, Afghan forces have suffered heavy casualties battling the Taliban, who have at times overrun provincial capitals before being pushed back. 
  
 Meanwhile, NATO and U.S. casualties have been few. In August, an American soldier was killed and another wounded by a roadside bomb in Afghanistan' southern Helmand province. In January, a U.S. soldier was killed by small arms fire near the Marjah district, also in Helmand. 
  
 The fight in Afghanistan — American's longest war — began after the Sept. 11, 2001 attacks as the Taliban harbored al-Qaida leader Osama bin Laden. The Taliban and Afghan government recently held secret talks to see if they could start peace negotiations to end the fighting, though questions remain over which faction of the insurgency is doing the talking. 
  
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 Gambrell reported from Dubai, United Arab Emirates. Follow him on Twitter at www.twitter.com/jongambrellap . His work can be found at http://bigstory.ap.org/content/jon-gambrell . ||||| KUNDUZ, Afghanistan (Reuters) - Dozens of Afghan civilians were killed on Thursday in air strikes called in when U.S. and local troops came under heavy fire during an operation in the north of the country in which two American service members also died. 
  
 Afghan officials said there was heavy fighting overnight in the village of Buz Kandahari, about 5 km (3 miles) from the center of the city of Kunduz, which Afghan Taliban fighters succeeded in entering as recently as last month. 
  
 Air strikes called in to protect U.S. and Afghan special forces conducting the operation caused heavy casualties. 
  
 “Unfortunately more than 30 civilians, including women and children, were killed during the fighting. This was a horrible incident,” said Asadullah Amarkhil, the governor of Kunduz, adding that dozens had been wounded. 
  
 There were angry protests by civilians who brought the bodies of many of the dead into Kunduz, which saw major battles in early October. 
  
 “These bodies you see here are either children or women, they are not Taliban. All innocent children and women killed here - look at the bodies there,” said Gull Ahmad, pointing to the bodies of relatives who were killed in the strikes. 
  
 In a statement, the U.S. military said the troops came under attack while working with Afghan partners to clear a Taliban militant position and disrupt the group’s operations in the district around the city. 
  
 “As part of an Afghan operation, friendly forces received direct fire and air strikes were conducted to defend themselves,” said Brigadier General Charles Cleveland, of the NATO-led Resolute Support mission. 
  
 “We take all allegations of civilian casualties very seriously.” 
  
 In a statement, the Taliban said American forces were involved in a raid to capture three militant fighters when they came under heavy fire. An air strike hit the village where the fighting was taking place, killing many civilians. 
  
 U.S. Secretary of Defense Ash Carter said he was “deeply saddened” to learn that two U.S. service members had been killed and four injured in Afghanistan. 
  
 “Our service members were doing their part to help the Afghans secure their own country while protecting our homeland from those who would do us harm,” he said in a statement. 
  
 According to Pentagon data, 1,832 other U.S. service members have been killed in action in Afghanistan since 2001, when U.S.-backed forces toppled the Taliban regime. 
  
 KUNDUZ SECURITY IN PERIL 
  
 The violence underlines the precarious security situation around Kunduz, which Taliban fighters came close to over-running last month, a year after briefly capturing it in their biggest success of the 15-year-long war. 
  
 While the city itself was secured, the insurgents control large surrounding areas. 
  
 The U.S. military gave no details of the identity of the two personnel killed, their units or the circumstances of their deaths. 
  
 Although U.S. combat operations against the Taliban largely ended in 2014, special forces units have repeatedly engaged in fighting while assisting Afghan troops. 
  
 Masoom Hashemi, deputy police chief in Kunduz province, said police were checking if any of the dead had Taliban links. 
  
 Thousands of U.S. soldiers remain in Afghanistan as part of the Resolute Support training and assistance mission and a separate counterterrorism mission. 
  
 The deaths come a month after another U.S. service member was killed on an operation against Islamic State fighters in the eastern province of Nangarhar. 
  
 Afghan forces, fighting largely on their own since the international combat mission ended, have suffered thousands of casualties, with more than 5,500 killed in the first eight months of 2016. |||||
What is a one-paragraph summary of the above article?
– Two US service members were killed Thursday battling Taliban insurgents in Afghanistan alongside local troops, reports the AP, rare combat deaths for American forces who largely handed over securing the nation to Afghan troops some two years ago. NATO described the Americans killed and two other Americans wounded in the assault as being part of "a train, advise, and assist mission" in Afghanistan's Kunduz province. They have not been identified. Kunduz officials later said they were investigating claims that local civilians also were killed in the fighting, possibly in a retaliatory airstrike. Taliban fighters briefly overran the city of Kunduz in early October, a show of strength by the insurgents that also highlighted the troubles facing local Afghan forces 15 years after the US-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 US airstrikes. Though US combat operations are officially over, thousands of US troops remain in Afghanistan, and special forces routinely accompany Afghan forces on missions, notes Reuters. (Afghanistan's own refugee crisis is beyond grim.)