ISLAMABAD: ISI Chief Lt-Gen Shuja Pasha left on Friday for Washington to explain Pakistan's position on the presence of Al Qaeda leader Osama bin Laden in the country before he was killed in a US raid on May 2.

Gen Pasha set off on the critical mission for putting an end to misgivings about Pakistan in the US a day after army's top brass conceded the failure of intelligence in detecting Osama's presence in the vicinity of the elite military training institute and ordered an investigation.

Uncorroborated reports suggest that before leaving for Washington Gen Pasha met CIA's station chief in Islamabad and reminded him about ISI's contributions in the war on terror and the lead about Osama's courier that eventually led the US to the Al Qaeda chief's hideout in Abbottabad.

Although, Washington does not have any evidence to prove that Pakistani military and intelligence were aware of Osama's presence in the country, it has put the onus on Pakistan to prove its innocence.

Pakistan is now being asked to do something that could prove its sincerity and commitment to the fight against militancy.

While defending ISI, Foreign Secretary Salman Bashir said: “It is easy to say that the ISI and elements in the government are in cahoots with the Al Qaeda. This is a false hypothesis. This is a false charge. It cannot be validated on any account. It flies in the face of what Pakistan, particularly the ISI, has been able to accomplish more than any other agency, including the CIA.”

As Gen Pasha left for Washington on a trip aimed at restoring trust, The Daily Beast, an online sister publication of Newsweek, reported that “the head of Pakistan's … intelligence service may step down, as the government looks for a fall guy for the Bin Laden debacle”.

The Daily Beast said Gen Pasha's resignation “was only a matter of time”.

The report about possible resignation of Gen Pasha has struck a chord with the general public who feel to have been let down by the army and ISI, not just because they could not notice the presence of world's top most fugitive, but also because of their failure to know about the raid by US Navy Seal strike team.

If anything could indicate public anger about the military and ISI it was a text message widely circulated on different cellular networks. The message reads: “For sale! obsolete army radar, can't detect copters, but can receive signals of Star Plus (an Indian entertainment channel). Only Rs999.”

Even though the Corps Commanders' Conference held on Thursday tried to allay public doubts about military's capabilities, reservations linger because of numerous unanswered questions regarding Osama's presence and the US raid.