KATHMANDU - Climbers returning from Mount Everest and other Himalayan peaks are struggling to find a return flight back home after Nepal banned most air travel to contain a surge in COVID-19 cases, mountaineering operators and hikers said on Wednesday.

Most regular international flights are closed through June as a deadly second wave of the coronavirus hit the Himalayan nation tucked between China and India.

Nepal issued 742 permits – 408 of those to climbers aspiring to make it to the top of the world's highest peak, Mount Everest – in the April-May climbing season. And hundreds of climbers are now returning from the mountains before the onset of annual monsoon rains.

Tashi Lakpa Sherpa, a senior official at Kathmandu-based private firm Seven Summit Treks, said climbers were finding it difficult to get home as only five weekly flights - to India, Qatar and Turkey - were operational.

"The situation could worsen as more climbers wind up their expeditions and return to Kathmandu in the next few days," Sherpa told Reuters.

Andrew Hughes, from the United States, said he had to pay for an expensive seat on a chartered flight to Qatar on Wednesday night due to the shortage of regular flights.

"We find ourselves in a situation where there is no transparency or rationale for the prohibition of outbound flights for foreign nationals," said Hughes, who returned from Everest last month.

Mexican climber Viridiana Alvarez, who had been stranded in Nepal for nearly three weeks after climbing Mount Annapurna, the world's tenth highest peak at 8,091 metres (26,545 feet), said she was lucky to find a seat on a chartered flight.

"There is no reason to be here because there is no climbing … it is a little boring," said Alvarez, 38, who is also flying to Qatar on Wednesday night.

The Nepalese government has defended its decision to cut international flights in a bid to contain the pandemic.

"Instead of having no flight at all, I think this is enough for now," Raj Kumar Chettri, a spokesman for the Civil Aviation Authority of Nepal (CAAN) said. "If required we'll allow more charter flights."

(Reporting by Gopal Sharma; Editing by Angus MacSwan) ((gopal.sharma@thomsonreuters.com; + 977 1 4372152; Reuters Messaging: gopal.sharma.reuters.com@reuters.net))