Two US soldiers have been killed fighting Taliban insurgents in northern Afghanistan, Nato has confirmed.
Nato said the personnel who were killed, and two others who were wounded in the assault, were part of "a train, advise and assist mission" in Afghanistan's Kunduz province.
In a statement, General John W Nicholson, commander of US Forces-Afghanistan, said: "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."
Kunduz local officials said an unknown number of civilians were also killed in the fighting, according to Associated Press.
Nato's combat operations ended in Afghanistan at the end of 2014 when it handed over the country's security to Afghan forces.