A member of the All India Anti-Terrorist Front (AIATF) gestures in front of a portrait of al-Qaeda leader Osama bin Laden during a pro-US rally as the group celebrates bin Laden's killing, in Noida in the northern Indian state of Uttar Pradesh May 5, 2011.[Photo/Agencies]

WASHINGTON - Osama bin Laden was aware of the plot in which al Qaeda militants bombed London transport facilities on July 7, 2005, but it was the last successful operation he played a role in, US government experts have concluded.

Circumstantial evidence, including information gathered from the Abbotabad, Pakistan, hide-out where US Navy SEALs killed bin Laden on May 2, also suggests that bin Laden had advance knowledge of an unsuccessful London-based 2006 plot to simultaneously bomb US-bound transatlantic flights, several US national security officials said.

"Bin Laden was absolutely a detail guy. We have every reason to believe that he was aware of al Qaeda's major plots during the planning phase, including the airline plot in 2006 and the London '7-7' attacks," one of the US officials told Reuters. This official and others spoke on condition of anonymity to discuss counter-terrorism matters.

Some of the confidence US officials expressed about bin Laden's involvement in the London attacks is based on analytical judgment rather than ironclad proof. Two of the officials said that there was no "smoking gun" evidence proving that he orchestrated the plots.

However, they and other US officials said there is strong evidence, including material collected from bin Laden's lair, indicating that, as the London-based plots unfolded, bin Laden was in close contact with other al Qaeda militants. One official said bin Laden was "immersed in operational details" of the group's activities.

"We believe he was aware of these plots ahead of time," one of the officials said.

Fifty-two civilians, and four suicide bombers, died in the July 7, 2005, attacks on three London underground trains and a double-decker bus. Hundreds were injured. It was "the last successful operation Osama bin Laden oversaw," a second official said.

The latest assessments from US and other Western officials support assertions by the Obama administration that, despite years of apparent isolation in Abbotabad, bin Laden still managed to keep in touch with activities -- sometimes in considerable detail -- of his followers around the world.