A pilot was killed and a US passenger critically injured in southern Afghanistan on Sunday when their helicopter came under fire in an attack claimed by rebels from the ousted Taleban militia.
A spokesman for the US embassy in Kabul initially said the pilot was British, but subsequently said there was confusion over his nationality.
The attack happened around 60 km (40 miles) south of Kandahar at about 11 am (0630 GMT).
The helicopter belonged to US construction company Louis Berger Group Inc, which oversees reconstruction work on the main highway linking Kabul with Kandahar in the south.
The rebels claimed responsibility for Sunday's attack, saying that people on board were spying on the Taleban and using the opening of a school as an excuse to fly over the area. Sources among contractors hired by Louis Berger said there were at least five people on board the helicopter, including two Afghans.
The pilot was killed and the passengers were all injured, at least one seriously.
The US embassy spokesman said the American passenger was a woman who specialises in health clinics. He added that it was not clear whether the helicopter was shot down or landed after coming under small arms fire, or if the casualties were caused by shooting or a crash landing.