The situation along Nepal's Trishuli River remains tense as water levels continue to rise following the devastating floods and avalanche in Tibet. NDTV's Vishnu Som reports from Bidur, where the road leading towards the China border has been cut off. Authorities are also watching an artificial barrier of rocks and debris upstream, amid fears that its collapse could trigger further flooding. Helicopters are being used to evacuate survivors and rescuers, while hundreds remain missing.