Chinese authorities have begun constructing what will be the world’s largest hydropower dam in Tibetan territory, in a project that has sparked concerns from India and Bangladesh.

Chinese Premier Li Qiang presided over a ceremony marking the start of construction on the Yarlung Tsangpo river on Saturday, according to local media.

The river flows through the Tibetan plateau. The project has attracted criticism for its potential impact on millions of Indians and Bangladeshis living downriver, as well as the surrounding environment and local Tibetans.

Beijing says the scheme, costing an estimated 1.2tn yuan ($167bn; £125bn), will prioritise ecological protection and boost local prosperity.