Reporting from Kandahar, Afghanistan — An explosion in southern Afghanistan on Thursday killed eight U.S. troops, officials said, an unusually large toll for a single incident.
Earlier in the day, NATO's International Security Assistance Force, or ISAF, announced the death of a service member in a helicopter crash in Afghanistan's east. The cause of the crash was under investigation, the coalition said.
A Pentagon official confirmed that the eight killed in the south were U.S. soldiers. Most of the troops in the south and the east are Americans. U.S. troops make up about two-thirds of the overall NATO force.
The deaths come as Western commanders are seeking to consolidate military gains, particularly in the south, before a U.S. troop drawdown set to begin next month. The scale of the pullback has not been set, and senior officials have said it will depend on battlefield conditions.
The Taliban and other insurgent groups have been weakened over the last year by a relentless campaign of targeted strikes, almost all of them led by U.S. special operations forces and aimed at wiping out the insurgency's mid-level field command.
But powerful insurgent-planted bombs, or improvised explosive devices, remain a deadly threat to Western troops. Such bombs kill and maim many Afghan civilians as well.
Over the last two months, the Taliban and groups such as the Pakistan-based Haqqani network also have carried out a series of attacks against Afghan government and military installations, which tend to be "softer" targets than Western bases. Recent high-profile targets have included the governor's compound in the southern city of Kandahar and a military hospital in the capital, Kabul.