A major flash flood hit Nepal’s mountainous Rasuwa district on Wednesday, washing away villages and damaging roads, bridges and hydroelectric projects, officials said. The affected areas are near the border with Tibet.Flash flood hits Nepal's villages, roads and bridges washed away. (Reuters)Syapru Besi and Timure were among the worst-hit areas in the district, which has a population of about 50,000. Authorities urged people living along the Bhote Koshi river to move to higher ground as they assessed the extent of the damage and feared possible casualties, Reuters reported.Authorities warn of possible casualtiesDistrict administrator Narendra Pariyar said several villages and infrastructure project sites had reportedly been washed away."We have reports of villages and infrastructure project sites being washed away," district administrator Narendra Pariyar told Reuters."There could be heavy casualties or loss of property," he added. "But I cannot say for sure now."Officials said there was no immediate estimate of deaths or property damage.Roads, bridges and power projects damagedThe cause of the flooding was not immediately known. However, officials noted that a deadly flash flood on the same river last year was later linked to the draining of a glacier lake.Nepal’s water resources ministry said hydroelectric projects were among the infrastructure affected by the latest flooding. Roads and bridges were also damaged, disrupting electricity supplies in the area.Prime Minister Balendra Shah said rescue and relief teams, along with police and military personnel, had been sent to support the response."Instructions have been given ... to move the people living in the lower areas to safer places," he said."People along the river are advised to exercise extra caution and remain alert."Bhote Koshi river flows towards IndiaThe Bhote Koshi river originates in Tibet before entering Nepal, where it joins the Trishuli river. The Trishuli eventually flows into India as the Gandak river.The region was hit by another deadly flood last year. The disaster killed nine people and left 24 missing, while a 'Friendship Bridge' connecting Nepal and China was washed away, disrupting trade and transport for months.A regional climate monitor later linked that flood to the drainage of a supraglacial lake in Tibet.(With inputs from Reuters)