The Civil Aviation Authority of Nepal said that four of the passengers are US citizens, one is a Japanese citizen and one a British citizen. Their identities were not immediately confirmed.

The 14 people on board are not likely to be alive, Home Ministry spokesman Jaya Mukunda Khanal said.

The aircraft was flying to the Everest region of Nepal from Kathmandu when it was diverted back to the capital because of poor weather.

A police rescue team was headed to the mountains in the Makwanpur district, about 100 kilometers (62 miles) southeast of Kathmandu, Khanal said. Local reports quoting eyewitnesses said the plane crashed into an agricultural field and broke into pieces.