India, Oct. 12 -- Siang, a river that has sustained generations of indigenous communities in Arunachal Pradesh, is now at the centre of protests over a proposed hydropower project that the government says has geostrategic importance.

The state government sees the 11,200-MW Siang Upper Multipurpose Project (SUMP) as a strategic safeguard against China's massive hydropower development upstream, but those who call the banks of the river home in Arunachal Pradesh fear displacement, ecological destruction and the loss of ancestral land.

What began as opposition to preliminary survey activities has escalated into violent clashes between villagers and security forces, competing claims of injuries, arrests and allegations of restrictions on jou...