Testifying before a Congressional subcommittee, James W McJunkin, deputy assistant director, counter-terrorism division of FBI, said the co-operation between the investigative agencies of the two countries have added a new dimension to the Indo-US relationship.

"One key lesson of the Mumbai attacks have reinforced is the importance of international partnership," McJunkin said appearing before the house committee on homeland security subcommittee on transportation security and infrastructure protection.

The subcommittee had convened a hearing on "The Mumbai Attacks: A Wake-Up Call for America's Private Sector." McJunkin said, "We will continue to work with our Indian counterparts in India and around the world, to bring the perpetrators of these attacks to justice and to prevent further attacks."

"The unprecedented collaboration we developed with our Indian law enforcement and intelligence counterparts in this investigation has strengthened our relationship with the Government of India," he added.

Referring to the statements made by the FBI Director Muller during his recent trip to India and Pakistan, McJukin said terrorism is not an issue for one country alone, all are fighting against it.

He said the principal lesson from the Mumbai attacks remain that a small number of trained and determined attackers with relatively unsophisticated weapons can do a great deal of damage.

"Last weeks attack on the Sri Lankan cricket team in Lahore [Images], is another example of a low-tech, but potentially high-impact operation," he said.

"We are concerned about the possibility that other terrorist groups, including the Al Qaeda [Images] or its affiliates will take note of these attacks and attempt to emulate them," McJunkin added.