KABUL, Afghanistan (AP) -- U.S. officials say three of the seven Americans who were killed were special operations forces -- two Navy SEALS and a Navy explosives expert.
A spokesman for the NATO coalition in Afghanistan says it's investigating the cause of today's crash of a Black Hawk helicopter in Kandahar province that killed seven American troops and four Afghans.
U.S. officials say initial reports indicated that the chopper was not shot down, but the Taliban claim that their fighters did, in fact, shoot down the aircraft.
The crash marked another deadly day for the U.S. in Afghanistan, less than a week after six American service members were gunned down -- apparently by two members of the Afghan security forces they were training.
The spike in U.S. deaths and the attacks from within the Afghan military have raised fresh doubts about the U.S. plan to leave a capable Afghan government in place when most U.S. and coalition troops depart.
The province where today's crash took place is a traditional Taliban stronghold. It's the spiritual birthplace of the hardline Islamist movement.