The border between China and Nepal is complicating the search for some Australians missing after the catastrophic floods that hit the region.
Family members desperate for answers are appealing for more information from Chinese authorities and more assistance from the Australian government.
Many of the 43 Australians missing after the disaster were pilgrims trekking from Nepal into Tibet to visit Mount Kailash, a revered site in four different religions.
Thousands of people visit the Himalayan peak each year, and multiple tour groups have reported people missing in the disaster.
One group of 80, including 11 Australians, had just finished the spiritual journey when the floods swept through the region.
The leader of the Isha Foundation tour sent a text message at 9:05am, Nepal time, saying they had arrived at the immigration post to cross back from Tibet into Nepal.
Ten minutes later, a wall of water, ice and debris triggered by a glacial collapse swept through the valley.
"The immigration office complex has been completely washed away," a spokesperson for the Isha Foundation said.
It is not clear how many people from the tour had officially passed through the checkpoint.
Husband of missing Australian 'helpless' without China's co-operation
Bhavin Patel's wife Reshma was part of the Isha Foundation group, and he has flown from New South Wales to Nepal to search for her.
He believes she is alive and has said the family is "desperately seeking assistance" to find her.
"I just want some help to bring Reshma back home," he told the ABC.
Mr Patel has checked her phone signal data and says it shows a connection in Tibet in the hours after the flood.
Chinese state media yesterday reported six Australians were among the 261 foreign nationals unaccounted-for on the Chinese side of the border.
Mr Patel is hoping satellite technology combined with his wife's phone data could assist in the search, but he said better coordination between China, Nepal and Australia was urgently needed.
"We are ready to share [the phone data]," he said.
"The Chinese government has got their own technology, so we try to get something from there, but we're not able to get anything from there."
Mr Patel said he felt "helpless" and wanted Australia to do more.
He has visited hospitals in Kathmandu, scanning lists of survivors, as well as meeting with the Isha Foundation and embassy officials.
Tour group offers 'phone signal information'
Nava Pandey's wife, Sumi Adhikari, also completed the pilgrimage with the Isha Foundation, and he too has travelled to Nepal searching for answers.
He earlier appealed for the Chinese government and local authorities "to release all available verified information, provide regular updates about the search efforts and establish direct communication with the affected families".
Chinese authorities are conducting search-and-rescue operations in the border crossing area, but they have faced criticism for a tight control on information and being slow to release details about the people missing there.
The border crossing site is one of the hardest-hit areas, and it has been cut off, with rescuers only reaching it on Friday.
Chinese state media reported teams crossed mountains and used ropes to rappel down slopes to reach the site, with one rescuer saying, "as far as the eye could see, there was nothing but ruins".
The Isha Foundation said its group's information had been provided "to the frontline rescue teams" and "additional phone-signal information" was being shared "to assist with the search".
Criticism also directed at Australian government
Kailash Journeys, another company that takes pilgrims to the mountain, has posted a photo on social media taken in Kathmandu before its trek departed.
The people in the picture are now all missing.
"If you recognize anyone in this photo — or have any information, however small, about the group's whereabouts — please contact us immediately," the caption reads.
Brisbane woman Aarti Raval's husband, Bhavinkumar Raval, is sitting on the ground in the photo, smiling.
He had gone on the Kailash Yatra pilgrimage with her cousin, Karan Bhardwaj, and their friend, Arpan Mithalal Kothari.
"I am having nightmares every night of my loved ones stranded in the jungle or stuck in the mud," she told the ABC.
She believes he is still alive and is making plans to travel to Nepal, saying she needs to "be there when he is rescued".
She has been critical of the amount of information being provided by the Australian government, including about which side of the border missing people may have been on.
The Australian government has said it is doing "everything we can" to "confirm (the) welfare" of the missing 43 Australians and "support their loved ones".
"This is an extremely anxious time for their families and loved ones," it said.
"They are understandably desperate for news, and our thoughts are very much with them."
It said the "extraordinary scale of this disaster, conditions on the ground and the remoteness of the affected region" had created "immense challenges" for rescue operations.
