The US is rushing a team of FBI investigators and forensic scientists to Mumbai as counter-terrorism officials were reported to be stunned at the level of coordination in the terror attacks in the city.
The FBI team would coordinate with Indian intelligence and security agencies about the planning and evidence collected on the attacks, a media report in New York said.
The US officials estimate that the widespread carnage could have been carried out for relatively small price tag of between $100,000 and $200,00O which, they say, is the cost of machine guns, grenades, ammunition and boats used, said ABC News.
The television network said intelligence agencies around the world are scrambling to identify the source of this latest threat in view of the "remarkable" coordination and sophistication.
The command centres, set up by terrorists in places they attacked, may have allowed them to communicate from site to site. The attacks, US officials said, appear to mimic Al Qaeda tactics simultaneous attacks on high profile targets in the heart of the financial district.
What is deeply disturbing to US law enforcement officials, the report said, is that these militants may now be targeting Westerners, particularly Americans, to draw attention to their cause, despite not having a specific grievance against the United States.