KATHMANDU, Nepal - All 22 passengers and crew on board a small passenger plane that crashed in a mountainous area in eastern Nepal were killed, police said on Thursday, after a rescue team reached the site.

The Twin Otter plane carrying three crew and 19 passengers including one American smashed into a mountainside shortly after taking off from a small airstrip 140 km east of Kathmandu on Wednesday afternoon.

Relatives grieve as bodies of victims killed in a Tara Air plane crash arrive in Kathmandu December 16, 2010. The Twin Otter aircraft 9N-AFX, operated by Tara Air between Lamidanda and capital Kathmandu, had lost contact shortly after takeoff on Wednesday from the mountainous airstrip and probably ploughed into the 9,000-feet-high hill, killing all 22 people onboard, officials said. [Photo/Agencies]

"We have recovered 20 bodies. We are still searching for the other two, but we can be sure there are no survivors," police spokesman Bigyan Raj Sharma told AFP.

"The aircraft has broken up completely and is scattered over 200 meters of dense forest."

It is not yet known what caused the Tara Air plane to crash.

Sharma said the bodies of the victims would be flown by helicopter to Kathmandu later on Thursday.

The United States embassy in Kathmandu confirmed that one was an American citizen and said it was in contact with the man's family.

The other passengers were initially thought to have been Nepalese, but media reports suggested they may have been Bhutanese pilgrims who claimed to be locals to qualify for a cheaper air fare.

This could not immediately be confirmed, but Sharma said identity documents from Bhutan had been found at the crash site.

Khotang, the remote district in eastern Nepal where the plane took off, is not a major tourist destination, but it is home to two sites of religious significance, a Hindu temple and a Buddhist monastery.

Air travel is popular in Nepal, which has only a very limited road network. Many communities, particularly in the mountains and hills, are accessible only on foot or by air.

The bodies of victims killed in a Tara Air plane crash arrive in Kathmandu Dec 16, 2010. [Photo/Agencies]

Aviation accidents are relatively common, particularly during the summer monsoon, when visibility is usually at its worst.

Last month a helicopter crashed near Mount Qomolangma (or Mount Everest as is known in the West) during a mission to rescue two stranded climbers, killing the pilot and an engineer.

In August, a plane headed for the Qomolangma region crashed in bad weather killing all 14 people on board, including four Americans, a Japanese and a British national.

An investigation blamed the crash on a power failure. It said the plane's generator failed and the pilot did not follow the proper procedures to conserve the remaining battery power.

Tara Air is a subsidiary of Yeti Airlines, a privately owned domestic airline founded in 1998 that runs a service to many remote destinations across Nepal.

Yeti's last major accident was in 2008 when a passenger plane crashed on landing at Lukla airport, the gateway to Mount Qomolangma, killing all 19 people on board.

Agence France-Presse