The security forces including the elite National Security Guard were "sluggish" in responding to audacious 26/11 terror attacks in Mumbai which claimed 166 lives a year ago, US think tank Stratfor has said.

The agency also said the "complex" working of Indian intelligence bureaucracy "doesn't allow for rapid warning" and that the country continues to face many of intelligence challenges that made the attacks possible.

"Even elite NSG were extremely sluggish in responding to the Mumbai attacks," Reva Bhalla, Director-Analysis, Stratfor, said.

She said India has attempted to make improvements to its coastal security since the Mumbai attacks and it remains to be seen how effective those measures are.

"But it is also apparent that India continues to face many of the intelligence challenges that made the Mumbai attacks possible in the first place... the diffuse and complex nature of India's intelligence bureaucracy doesn't allow for rapid warning," she said in an interview.

The think tank said while armed assaults like that of Mumbai are becoming popular tactic in global terrorism, the country is yet to develop a highly trained force to combat terror threat and building the capabilities and capacities of "street cops".