According to officials, a NATO helicopter crashed in eastern Zarmat city in Paktia province on Monday, but the possible number of casualties are not known, a Press TV correspondent reported.
However, the Taliban claim that at least 33 US soldiers have been killed in the second downing.
The NATO forces have cordoned off the scene of the incident, witnesses told Press TV.
The incident came in the wake of a similar incident on Saturday, which claimed the lives of 31 US forces.
The Taliban claimed responsibility for the Saturday helicopter crash, but NATO said it has started an investigation into the incident.