The crash is under investigation, but the US-led coalition told the Associated Press that there were no reports of enemy activity in the area at the time.
The names and nationalities of those killed will not be released until the families and governments have been notified. The helicopter was allegedly a U.S. Marine CH-53 Sea Stallion according to CBS News.
Although helicopter-related deaths are not rare, crashes usually take the lives of one or two soldiers rather than six. The crash Thursday is the deadliest reported since Aug. 6, 2011 when 38 soldiers were killed after a Taliban fighter fired a rocket-propelled grenade at the NATO US CH-47 Chinook helicopter. The August incident took the lives of 30 American soldiers and eight Afghans in what was the deadliest single event for American forces since the beginning of the war in Afghanistan in 2001.
The newest incident brings the death toll of NATO troops this month up to 28, fewer casualties than the 32 deaths in January of last year.
The helicopter crash coincided with other deadly incidents in the region on Thursday.
A rogue Afghan soldier opened fire on French troops at a base shared by French and Afghan forces in the Tagap valley, killing four French soldiers and wounding others. The attack has caused French President Nicolas Sarkozy to question France's involvement in the war and he has halted all training operations in Afghanistan.
I would like to express my condolences for the four French soldiers who were killed today and my sympathy to those who were wounded. I pay tribute to the service and sacrifice of all our troops in Afghanistan, NATO Secretary General Anders Fogh Rasmussen said in a statement.
Seven civilians were also targeted in a suicide bomber attack Thursday outside a crowded gate at Kandahar Air Field, a base for U.S. and NATO operations. The suicide bomber set off a car full of explosives as two pick-up trucks were leaving the U.S. base, the AP reports. The Taliban claimed responsibility for the attack.
The attack was the second suicide bombing in southern Afghanistan in the past two days.
The U.S. has continued to pursue plans to broker talks between the Taliban and President Hamid Karzai's government in Afghanistan in an effort to end the war and have a complete transition before the 2014 NATO withdraw deadline.
Related Article: Afghan Soldier Kills Four French Troops; Sarkozy Shaken