Rescuers used drones and abseiled down a deep gorge on Tuesday looking for the last missing person from Nepal’s worst air disaster in 30 years, in which at least 71 people died, including small children.

Difficult terrain around the 650ft gorge and poor weather were hampering rescue efforts near Pokhara, where the Yeti Airlines’ 9N-ANC ATR72 aircraft carrying 72 people crashed on Sunday just before landing.

The search was called off after darkness descended, and will resume on Wednesday, said Tek Bahadur K.C., a top district official.

Rescue teams were struggling to identify bodies, Ajay K.C, a police officer in Pokhara who is part of the rescue efforts, told Reuters.

“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 were in flames,” he said before the search was suspended for the night.

Rescuers had collected what appeared to be human remains and sent them for a DNA test, he said, but search efforts would continue until all 72 passengers and crew were accounted for.

“There were small children among the passengers,” K.C. said. Search teams found 68 bodies on the day of the crash, while two bodies were recovered on Monday before the search was called off.

One more body had been recovered as of late Tuesday afternoon, said Prakash Pokhrel, an official coordinating rescue operation at Kathmandu airport.

An airport official said 48 bodies were brought to the capital Kathmandu on Tuesday and sent to a hospital for autopsies, while 22 bodies were being handed over to families in Pokhara.

Medical personnel in personal protective equipment and masks helped transport bodies from stretchers to a vehicle before they were flown to Kathmandu.