US Democratic presidential frontrunner Hillary ClintonSenior Pakistani leadership knew that Osama bin Laden was hiding at a compound in Abbottabad but US has not been able to get any proof of it so far, said Hillary Clinton, who was the Secretary of State at the time of the operation and is presently the Democratic presidential front-runner.

Clinton, 68, was the top adviser to President Barack Obama on the decision to kill al-Qaida leader and world’s most dreaded terrorist bin Laden on May 2, 2011.

In an interview to the CNN broadcast on Monday, she said it was “just too much of a coincidence… that unusual-looking house would be built in that community near the military academy, surrounded by retired military professionals even though we could not prove it.

“There was never any evidence that we could uncover that led directly to the top of the Pakistani military and intelligence service. I believe Pakistanis knew,” she said.

CNN said Clinton will have to evaluate what is needed to continue the fight against al-Qaida should she take the White House.

But Obama’s aides stressed that the next commander-in-chief will for sure need a blend of the fine-grained intelligence work and surgical force that defined the lethal 2011 strike against al-Qaida’s mastermind, it said.

The US Navy Seals’ raid killed bin Laden in 2011 at his compound in Abbottabad town near Pakistan army’s elite training school.

Bin Laden was the founder of al-Qaida, the group that claimed responsibility for the September 11, 2001 attacks on the United States.