Washington: Pakistan supports groups that carry out terrorists activities, a former US counter-terrorism official has said, citing the close linkage it has with outfits like LeT that carried out the Mumbai terror attacks.

"Pakistan is unique because of the various groups that are there that have been supported by the Pakistani state, groups like the Lashkar-e-Taiba that have attacked in India, directed by Pakistani intelligence, murdering people in a hotel in Mumbai," Michael Sheehan, who was Coordinator for Counter-terrorism with the rank and status of Ambassador-at-Large from 1998 to 2000 at the US State Department, told lawmakers during a Congressional hearing on Monday.

"This is a unique situation where a state is actually involved in these organisations that are part of this stew I talked about earlier that directly threaten us," said Sheehan, who is currently Distinguished Chair, Combating Terrorism Center, US Military Academy at West Point.

Responding to a question from Congressman Scott Perry on direct links between members of the Pakistani government and the terrorist organisations, Sheehan said there is likely because of the decades old links between them.

"It's possible, especially the organizations that they might arm to attack in Kashmir or in India. Those same type of weapon systems can then be turned against us. But I don't believe the Pakistani army, the Pakistani government would count on such an activity. It would come from below perhaps from a rogue. I don't see any evidence of that happening right now. It's something we have to keep an eye on," Sheehan said.

Thomas Joscelyn, senior fellow, Foundation for Defense of Democracies, told lawmakers that these terrorist organizations are a wing of the ISI. He alleged that there is direct relationship between parts of the military intelligence establishment in Pakistan and al-Qaeda.

"I think those relationships do exist. I think the best way to fact-check that and get into what the actual relationship is and how that works is probably to have a more complete discussion about bin Laden's documents, the extensive files that were found in his compound and what they say," he said.

"(Terrorist groups allied with al-Qaeda) are sponsored by the ISI, that are creatures of the ISI establishment, are also allied with al-Qaeda. And that's part of how al-Qaeda gets the strategic depth. I lay it all out in great detail how that works, from the Afghan Taliban to Lashkar-e-Taiba," he said.

David Sedney, the former Deputy Assistant Secretary for Afghanistan, Pakistan and Central Asia, also alleged the ISI activities in this regard.

He said noted journalist Hamid Mir was the subject of an assassination attempt. Mir, before the assassination attempt, had communicated to his family that if such an assassination attempt took place, it was ISI that was trying to kill him.