India, Aug. 28 -- China has sounded a Level-IV alert following devastating flash floods at the Tibet-Nepal border, warning that a newly formed barrier lake at the confluence of two rivers faces a high risk of breaching and flooding downstream areas.

China's Ministry of Water Resources issued the emergency alert for the Tibet Autonomous Region on Thursday night, warning of the threat from the barrier lake, which formed near the confluence of the Chhochen Khola and Purepu Tsangpo rivers. These rivers originate in Tibet and flow into Nepal as part of the Bhote Koshi river system. China's four-level disaster response system runs from Level-I, the most severe, to Level-IV, the least.

The lake had accumulated an estimated two million cubic me...