The US-led International Security Assistance Force (ISAF) said the cause of the explosion was unclear, but that 26 people had been onboard the aircraft.
Eastern Afghanistan is one of the most volatile parts of the country, where Taliban and other Islamist insurgents have carved out a strong presence. It is just across the border from Pakistan, where militant groups have rear bases.
ISAF initially announced that 10 troops were wounded in the incident and two people were killed, but a spokesman later revised down the casualty statistics.
"Operational reporting is very fluid. You've got to understand that we're trying to get all the facts," an ISAF spokesman told AFP.
"There are seven wounded and one killed in action. It is up to respective governments to release the killed in action. The seven wounded are ISAF personnel," the spokesman said.
Another ISAF spokesman identified the aircraft as a US Chinook and said that the landing site had been secured by Afghan and NATO soldiers.
"The cause of the explosion is under investigation," the military said.
There are currently around 152,000 foreign troops under US and NATO command in Afghanistan, fighting in a bid to reverse a nine-year Taliban insurgency.
Two thirds of the troops are Americans.
