Searchers have deployed drones to search for two passengers still unaccounted for after Nepal’s deadliest plane crash in 30 years, which killed at least 70 people.

Some rescuers abseiled down the 200-metre (656-foot) deep gorge in search of the missing passengers. Officials say the hope of finding anyone alive was “nil”.

“There is thick fog here now. We are sending search and rescue personnel using ropes into the gorge where parts of the plane fell and was in flames,” Ajay KC, a police official in Pokhara who is part of the rescue efforts, told Reuters news agency on Tuesday.

Difficult terrain and inclement weather have been hampering rescue efforts near the tourist city of Pokhara, where Yeti Airlines’ ATR 72 turboprop with 72 people on board crashed in clear weather on Sunday just before landing.

Searchers found two more bodies on Monday before the search was called off because of fading light.

“There were small children among the passengers. Some might have been burned and died, and may not be found out. We will continue to look for them,” Ajay said.

Television channels showed footage of weeping relatives waiting for the bodies of their loved ones outside a Pokhara hospital where autopsies are being conducted.

Hospital staff on Tuesday began the grim task of handing over bodies to grieving families.

Up to 10 bodies were transferred by army truck from Pokhara hospital to the airport ready to be airlifted back to the capital, Kathmandu, the AFP news agency reported.

According to the Press Trust of India news agency, the plane’s pilot Anju Khatiwada joined Nepal’s aviation sector after her husband was killed flying a small passenger plane in 2006.

On Monday, searchers found the cockpit voice recorder and flight data recorder from the flight, both in good condition, a discovery that should help investigators determine what caused the crash.

Under international aviation rules, the crash investigation agencies of the countries where the plane and engines were designed and built are automatically part of the inquiry.

ATR is based in France and the plane’s engines were manufactured in Canada by Pratt & Whitney Canada. French and Canadian air accident investigators have said they plan to participate in the inquiry.

Nepal’s aviation industry has boomed in recent years, carrying goods and people between hard-to-reach areas, as well as ferrying foreign mountain climbers.

But the sector has been plagued by poor safety due to insufficient training and maintenance. The European Union has banned all Nepali carriers from its airspace over safety concerns.

Nepal also has some of the world’s trickiest and most remote runways, flanked by snow-capped peaks with difficult approaches and capricious weather.

Its deadliest aviation accident occurred in 1992, when all 167 people on a Pakistan International Airlines jet were killed when it crashed on approach to Kathmandu.