The Torsa River (also spelt Torsha and also known as Kambu Maqu, Machu and Amo Chhu) rises from the Chumbi Valley in Tibet, China, where it is known as Machu.

Its course continues into Bhutan, India, and Bangladesh before joining the Brahmaputra River into the Bay of Bengal.

From Tibet, the Torsa flows into Bhutan, where it is known as the Amo Chu.

[2] Afterwards, the river flows past the border towns of Phuntsholing (in Bhutan) and Jaigaon, and Hasimara (in India) and past the tea estate of Dalsingpara and the Jaldapara National Park.

Ghargharia river meets with Torsa in the Tufanganj subdivision, near Deocharai and Balarampur.