Rescue teams were working on Monday to reach more than 900 missing hydropower workers, hundreds of whom are feared trapped in the tunnels and underground areas of 11 hydropower projects in Nepal after the devastating flash floods, ​the ⁠country’s disaster ​management authority has said.The death toll from the ⁠unprecedented deluge of ice, rock, mud ​and debris on Wednesday last week has risen to 903, with 16 more dead reported in Tibet. Nearly 5,000 are missing on the two sides of the border.Two Irish citizens are among the missing in Nepal. They have been identified as Santosh Sahu and Spandan Sahu by the country’s department of tourism. The men’s names were among a list of more than 500 unaccounted for tourists published by the department last week. According to the department, Spandan is 18 and Santosh is 46.Rescue efforts are complicated by difficult terrain, persistently high flood waters and difficult weather. With more than 40 bridges destroyed, rescuers are relying on helicopters, while India and China are sending prefabricated truss bridges to help restore access.Rescue work continues in the aftermath of flash floods in Nepal's Nuwakot district. Photograph: Arun Sankar/AFP via Getty Images Covered bodies of victims as the Nepali army conduct search and recovery operations. Photograph: EPA A health worker sprays disinfectant following flash floods in Nepal's Nuwakot district. Photograph: Arun Sankar/AFP via Getty Images People salvage belongings from their home after flash floods in Nepal's Nuwakot district. Photograph: Arun Sankar/AFP via Getty Images The swollen Trishula river has also continued to change course unpredictably, making planning a challenge. Areas that were dry one day are flooded the next, and further floods are a constant concern.Hundreds of bodies, many unidentified, that were swept down the mountains by the torrent, have been buried in shallow graves on the plains ⁠of the Himalayan region following DNA testing.Nepali officials said on Monday that the focus was on reaching the 933 people missing from ‌hydropower plants. “A large amount of debris has been deposited and that is posing us a big challenge to open the tunnels,” the Nepali army spokesperson Raja Ram Basnet told Reuters news agency.About 250 people were rescued from the Upper Trishuli hydroelectric project over the weekend, and army engineers began blasting operations at the site to rescue another 42 workers thought be missing.The damage to hydropower infrastructure is estimated to have taken 700 megawatts out of service, about 10 per cent of the country’s power capacity. Pictures and videos shared by rescue teams ⁠showed earth-moving equipment shovelling mud to try to reach the tunnels.[ Nepal flood victims found 200km downstream as nearly 2,000 remain missingOpens in new window ]Ashish Gurung, who normally works as a guide, was among the rescuers. “There is just mud everywhere,” he said. “Inside the tunnel it was worse. It’s so difficult to move, the mud is so deep.”His team was trying to access the Chilime hydropower plant in Rasuwa, one of the worst-hit areas. At least eight people are believed missing there, and an Indian team is working alongside the Nepali army using pumps and excavators to locate them.The Nepali prime minister, Balendra Shah, said rescue efforts were “challenging due to adverse weather, difficult terrain and ongoing risks”.Gurung said mountaineers were improvising by using planks of wood to check the depth of the mud, before using them as makeshift bridges along with a system of ropes to keep themselves safe.“Walking in it is very difficult – at one point it was up to our chests,” he said. “We got close to the first station, about 130 metres in. Inside that far ... it looked like it was just bodies.”The hydropower company had given his team a map and it looked as if there was a chance people in the tunnels could have survived. “They have a safe area inside,” he said. “Some of them could potentially be alive. I am hoping they are alive.”[ ‘It was terror’: Survivors describe devastating force of Nepal floodsOpens in new window ]The Red Cross estimates that more than 93,000 people have been affected by the disaster, which China and some experts have linked to the climate crisis.Shah said the flood was an “unprecedented and devastating natural disaster” and that it was difficult to compile a complete assessment of the damage.“Despite the adverse weather, difficult terrain and continuing risks, we are moving forward with determination to save the lives of our citizens,” he said in a Facebook post late on Sunday. Almost 21,000 security personnel were involved in the rescue operations alongside civilian workers and volunteers, he said.Whole communities had been destroyed by the flooding, leaving families homeless in heavy rain.Nepal’s disaster agency said on Monday it had counted 903 deaths, with 4,793 people, including 592 foreigners, missing. Chinese authorities had reported 16 deaths and 546 people missing as of Sunday. State media said 261 of the missing were foreigners, including more than 100 Nepalis.China’s state-run CCTV said Beijing had mobilised more than 2,100 rescue workers and allocated at least ​220 million yuan (€28 million) to support relief efforts and had been airdropping equipment and supplies to frontline rescuers, while its soldiers used life-detection equipment to look for the missing.[ What triggered catastrophic flood on the Nepal-Tibet border?Opens in new window ]Nepal has said it does not need foreign help in general search-and-rescue operations, but it has leant on its neighbours, India and China, for their expertise in tunnel rescues.The flood was “caused by glacier instability under the long-term effects of global warming”, CCTV reported, saying ​it was a “new and prominent feature of cryosphere ‌disasters” on the Tibetan plateau.Two ​Nepali officials said China had ​not shared much information on glacier risks and water levels after a meeting to strengthen co-operation earlier this year, and they feared that could hamper future disaster preparedness.China’s foreign ministry said Beijing had continuously provided Nepal with meteorological and hydrological data and will continue to “strongly support” Nepal’s disaster relief efforts and safeguard the two countries’ common interests. – Guardian