Anushilan Samiti was an Indian fitness club, which was actually used as an underground society for anti-British revolutionaries. In the first quarter of the 20th century it supported revolutionary violence as the means for ending British rule in India. The organisation arose from a conglomeration of local youth groups and gyms (akhara) in Bengal in 1902. It had two prominent, somewhat independent, arms in East and West Bengal, Dhaka Anushilan Samiti, and the Jugantar group.

Ullaskar Dutta was an Indian revolutionary associated with Anushilan Samiti and Jugantar of Bengal, and was a close associate of Barindra Ghosh. He was the principal bomb maker of the Jugantar group until Hemchandra Kanungo returned from Paris learning political theory and explosive chemistry.