A small plane with 21 people on board and flying in poor visibility over mountainous terrain in Nepal on Wednesday has gone missing and feared to have crashed, officials said.

Domestic airline Tara Air said rescue helicopters had been deployed to search for the Twin Otter aircraft, which lost contact with air traffic control eight minutes after it left the western town of Pokhara on Wednesday morning.

“A plane that took off from Pokhara for Jomsom this morning is out of contact,” Tara Air spokesman Bhim Raj Rai told media.

“There are 18 passengers, including two foreigners, and three crew members on board.”

One passenger was later confirmed to be from China and another a Kuwaiti national. All the others were from Nepal and two were children.

“We have dispatched three helicopters on a search and rescue mission. We will provide updates as they come,” the airline said in a statement posted on its website.

“The weather at both origin and destination airports was favourable and the airport cleared for departure by the control tower at Pokhara,” said the statement.

A Nepal army spokesman, however, said fog was hampering the search for the Twin Otter plane.

“Our rescue teams have been deployed, but the weather was not clear in the morning,” said army spokesman Tara Bahadur Karki.

“They are still out looking at possible areas, but the plane has not been located yet.”

The police chief at Jomsom, Harihari Yogi, said they had reports from local villagers of hearing a loud explosion near the small village of Rupshe and attempts were being made to reach it.

Jomson, in the Himalayas, is about 20 minutes’ flight from Pokhara, which lies 200km (125 miles) west of Kathmandu. It is popular for both foreign tourists visiting the Mount Annapurna and Mustang region for trekking, and for Hindu pilgrims visiting the Muktinath temple.

Airport official Yogendra Kuwar said there were no landing strips between the two airports and it is believed to have crashed.

Helicopters were searching the route more than two hours after the plane was to have landed, but poor weather conditions are making that difficult, he said.(Agencies)