TRISHULI, Nepal/BEIJING — Nearly 1,500 people including at least 800 foreigners are missing across Nepal and China's Tibet, authorities said on Thursday, after a wall of mud and rock collapsed into a Himalayan river, sending catastrophic floods through towns and valleys. Rescuers in Nepal used helicopters to search for survivors and drop emergency supplies to thousands cut off after Wednesday's disaster swept a rugged mountainous region thronged by trekkers and pilgrims linking Lhasa in Tibet with the Nepalese capital of Kathmandu. Police said they expected the death toll to rise beyond 165. "This will go up, as we have resumed the search and more bodies are expected to be recovered," police spokesperson Abi Narayan Kafle told Reuters. Almost 600 foreigners were among 826 people missing in Nepal, police and tourism officials said. Among the missing tourists from more than two dozen countries, 177 were from India, 63 were from the United States, 34 from Australia, 33 from Britain and 25 from Canada. The tally of missing in Tibet's Gyirong county was 558, Chinese state broadcaster CCTV s