"They are a very lethal terrorist group in their own right in India. They have carried out a number of attacks within India''s borders on innocent civilians, and although not confirmed, there''s a suspicion that they were responsible for the recent bombings in Mumbai on July 13," Mark Toner, State Department spokesman, said.
The sanction slapped on Indian Mujahideen by US Secretary of State Hillary Clinton sends a very clear message to the world that the US considers this to be an international terrorist organization.
He said the US and India would continue to work closely.
"Frankly its India that bears the brunt of these attacks.
We have a robust strategic dialogue with India. They are a close ally and partner. One of the elements of that is close counterterrorism cooperation," Toner said in response to a question.
"Yes, this (Indian Mujahideen) is the first Indian-based group the Department has designated as a FTO," a State Department official told PTI.
However, two other separatist groups, Babbar Khalsa International and International Sikh Youth Foundation -- were slapped sanctions under the Executive Order 13224 terrorist groups in June 2002.