Sri Lanka, Dec. 24 -- The killing of a man from a minority community during recent violent protests in Bangladesh has pushed already strained ties between Dhaka and Delhi into a deeper crisis.

As the two neighbours accuse each other of destabilising relations, questions are growing over whether their once close, time-tested relationship is fraying beyond repair.

In India, the episode has sparked protests by minority nationalist groups. The man who was killed - Dipu Chandra Das, 27 - a member of Bangladesh's minority group, was accused of blasphemy and beaten to death by a mob last week in Mymensingh, in northern Bangladesh.

The incident happened as violent protests broke out over the murder of Sharif Osman Hadi, a prominent student lea...