A helicopter belonging to a private company has gone missing in war-torn eastern Afghanistan, where NATO troops are searching for the aircraft, officials said Thursday.

- We're assisting in the search for a missing helicopter in eastern Afghanistan - said Lieutenant Colonel Todd Vician, a spokesman for the NATO-run International Security Assistance Force (ISAF) based in Afghanistan.

The missing helicopter is a MI-8, a Russian transport helicopter equipped to carry up to 27 passengers and crew.

The ISAF spokesman said he was unable to say which company owned the helicopter or give details on the precise region the search was taking place for security reasons.

- There was information last night that a private helicopter had a hard landing in Kharwar district - said General Mustafa Mohsini, police chief in the eastern province of Logar.

The district of Kharwar is nearly 150 kilometres (94 miles) south of the capital Kabul and insurgents have a strong presence in the area.

- Together with the US-led coalition, Afghan police and Afghan army, we searched for it until noon today, but we did not find any sign of any helicopter - added Mohsini.

Taliban insurgents are numerous in much of eastern Afghanistan, where their armed campaign to unseat the Western-backed government is at its deadliest since the 2001 US-led invasion ousted their regime in Kabul.

On October 26, two helicopter crashes killed 14 US troops and narcotics agents in one of the blackest days for the United States in Afghanistan.