KATHMANDU — A massive flash flood in the Himalayan nation of Nepal washed away villages while damaging roads, bridges and power projects in a region bordering Tibet, authorities said on Wednesday, as they warned against the risk of casualties. The areas of Syapru Besi and Timure in the mountainous district of Rasuwa, with a population of about 50,000, were severely affected, officials said, while urging those living on the banks of the Bhote Koshi river to seek higher ground. "We have reports of villages and infrastructure project sites being washed away," district administrator Narendra Pariyar told Reuters, although no immediate estimates of casualties or property losses were available. "There could be heavy casualties or loss of property," he added. "But I cannot say for sure now." The reason for the inundation was not immediately clear but a deadly flash flood on the same river last year was eventually traced to the draining of a glacier lake. Nepal's water resources ministry said hydroelectric projects were among the infrastructure damaged by the floods, along with roads and bridge