The Indian junior minister for home affairs, I D Swami speaking in the Meghalayan capital, Shillong, said that if Bangladesh did not punish those guilty, India would find it harder to maintain friendly relations with its eastern neighbour.

Mr Swami said the Indian Border Security Force has filed a 'first information report' at a police station in Assam, accusing the Bangladesh Rifles (BDR) of torturing and killing the guards.

First step

The report, which is the first step towards bringing formal charges against the suspects, states that the Indian border guards strayed into Bangladeshi territory by mistake and were caught and killed.

It also says the bodies bore marks of mutilation when they were returned.

Bangladesh claims that the bodies were partially decomposed because they could not be removed from flooded paddy land for two days due to incessant firing by the BSF.

Mr Swami has already asked the BSF to maintain strict vigil on the borders with Bangladesh.

India is beefing up security near the border

Some observers in Assam say lodging a 'first information report' is a symbolic step, but that Mr Swami's announcement about petitioning the International Court of Justice may not hold much water in legal terms.

They say it is political rhetoric - with India's ruling Bhartiya Janata Party trying to come to power in state assembly elections next month.

The incident has come in handy for the BJP and its electoral allies to rake up a long-running issue about illegal immigration, which always provokes furious responses among the ethnic Assamese.