August was the deadliest month for the U.S. military so far in the decade-long war in Afghanistan.

A total of 66 U.S. troops died last month, topping by one the death toll for July 2010, which previously had been the deadliest single month for the United States in Afghanistan since 2001.

August's death toll includes the 30 U.S. troops killed in the downing of a Chinook helicopter by insurgents in eastern Afghanistan. The dead included members of the elite U.S. Navy SEALs. It was the worst loss of life for the United States in a single incident during the Afghan war.

Meanwhile, NATO said one of its service members died Wednesday in a bomb blast in eastern Afghanistan. The coalition did not provide any additional details.

More than 390 international troops have been killed in Afghanistan so far this year.

Taliban insurgents are increasingly using improvised explosive devices to target both security forces and Afghan civilians.

Last month, the United Nations said the number of deaths from roadside bombs increased by 17 percent this year compared to the same period in 2010, making them the single-largest killer of civilians in the first half of this year.