A small passenger plane heading to the Mount Everest region crashed in heavy rain Tuesday outside Nepal's capital of Kathmandu, killing all 14 people aboard, officials said.

The private Agni Air plane went down near Shikharpur village, about 80 kilometres south of Kathmandu, area police chief Ram Bahadur Shrestha said. The German-built Dornier airplane was carrying 11 passengers and three crew members when bad weather forced it to try to return to Kathmandu.

Tri Ratna Manandhar of the Civil Aviation Authority of Nepal confirmed there were no survivors. Four Americans, one Briton and one Japanese were among the dead, while the remaining passengers and crew were Nepalese.

Officials had earlier said there were five Americans on the plane.

Shrestha said rescuers were not immediately able to reach the crash site. The area has no roads and is only accessible by foot, but the route from the nearest town was blocked by a river flooded by monsoon rainfall.

Ram Bahadur Gole, a villager who witnessed the accident, told Avenues Television network that the crash impact broke the plane into several pieces that were scattered on a hillside.