NEW DELHI, Oct 5: India revealed on Tuesday that it was considering a US offer to ask FBI for probing last week's bomb attacks in the north-eastern states of Assam and Nagaland that killed 50.

The unusual announcement came within days of admission by New Delhi, following news reports, that it was allowing US-leased aircraft passage to ferry light arms to Kathmandu to help Nepal fight a major Maoist rebellion.

The US ambassador in India has made an offer of FBI assistance for investigation of the recent bomb blasts which have taken place in Assam and Nagaland, in terms of ongoing cooperation between our two countries on counter-terrorism, the Indian foreign ministry said in a statement. The offer will be considered in terms of the existing guidelines of the Indian government, it said.

Departing from the usual secrecy surrounding its security-related deals with foreign countries, New Delhi appears to have been forced to reveal the facts on the US offer after the Congress Party Chief Minister of Assam state, Mr Tarun Gogoi, spilled the beans on a letter from US ambassador David Mulford who offered help in the probe.

"Should you find it helpful that the FBI should be pleased to provide technical support for investigation. I have also made this offer to Home Minister Shivraj Patil. I hope you will be free to contact me if there is any other way that we can be helpful, Mr Mulford wrote.

The letter to Mr Gogoi further said: "In this context US has considerable expertise in investigative techniques. The people of America join you in hoping that the perpetrators of these crimes will be brought swiftly to justice.

Earlier, the United States strongly condemned the wave of violence in India's north-eastern states during the Oct 2-3 weekend.