Islamabad: Pakistan's Inter-Services Intelligence (ISI) chief Lt Gen Ahmad Shuja Pasha might quit after the debacle over Osama bin Laden, a media report said on Friday.

To ease both domestic and international anger and dismay over the presence of the al Qaeda leader in a military cantonment town close to the capital, senior Pakistani officials told a news website they recognise that an important head has to roll and soon.

They say the most likely person to be sacked is Lt Gen. Ahmad Shuja Pasha, the Director General of the country's spy agency, the ISI.

In a last-ditch effort to control the damage and to assure the US that the ISI was not harboring Osama and was unaware of his presence in Pakistan, Pasha reportedly flew to Washington on Friday.

But the high-level sources who refused to be quoted say his resignation is only a matter of time.

Pakistanis are furious that the ISI and the powerful military which controls national security policy, could have been incompetent as not to know that the al Qaeda leader was comfortably holed up in Abbottabad.

However, the report quoted a senior ISI officer as saying: "It's far from routine for someone to resign over failures. But someone has to resign."

A former ISI officer was blunter. "It was a great failure of, and an embarrassment to, Pakistani intelligence," he said. "The pressure is mounting for Pasha to resign."

Pakistani sources say that Pasha was never keen on the ISI job in the first place. He had no background in intelligence and was an infantry and armour officer in previous commands.

He was, however, very close to Kayani, who insisted him to take up the job when he was nominated in 2008.

Pasha's resignation will not affect the US probe of how Osama was able to hide right under the nose of the Pakistani military for so long.