Osama Bin Laden: Yusuf Raza Gilani denies collusion
Pakistan is to launch an investigation into how Osama Bin Laden was able to live in the garrison city of Abbottabad undetected, Prime Minister Yusuf Raza Gilani has told parliament.
But he insisted that allegations of Pakistani complicity and incompetence were "absurd".
US President Barack Obama has urged Pakistan to investigate the suspected network that sustained Bin Laden.
Mr Obama said it had to find out if any officials knew of his whereabouts.
In a statement to MPs about the raid by US special forces which led to the death of Bin Laden last week, Mr Gilani said Lt-Gen Javed Iqbal would lead the investigation into the failures to detect the al-Qaeda leader.
"We are determined to get to the bottom of how, when and why about OBL's presence in Abbottabad," Mr Gilani said.
He mounted a strong defence of Pakistan's record in fighting terrorism, highlighting the "price paid" in civilian and military losses, and the numbers of al-Qaeda militants killed or arrested.
There have been suspicions that someone in Pakistan's Inter-Services Intelligence (ISI) spy agency, which has a long history of contacts with militant groups, may have known where Bin Laden was hiding.
But Mr Gilani told MPs that the ISI, and the military, had the full support and confidence of the government.
He said the US raid was "a violation of sovereignty", and suggested that Washington had helped create al-Qaeda during the Soviet invasion of Afghanistan.
The US had then widely dispersed al-Qaeda's fighters by following a "flawed" military strategy to try to capture Bin Laden in the mountains of Tora Bora in 2001, he added.
"We did not invite al-Qaeda to Pakistan," he insisted, saying that the failure to find Bin Laden for 10 years was the result of "an intelligence failure... of all the intelligence agencies of the world" and that "blame games serve no purpose".
He added: "The al-Qaeda chief, along with other al-Qaeda operators, had managed to elude global intelligence agencies for a long time. He was constantly being tracked, not only by the ISI but also by other intelligence agencies.
"It was the ISI that passed leads to the CIA that enabled the US intelligence to use superior technological assets and focus on the area in which Osama Bin Laden was eventually found."
Despite his criticism of the US, he also said that Washington remained a key ally of Islamabad.
"We have a strategic partnership that we believe is in our mutual interest."
Meanwhile, a crowd of about 500 people demonstrated in Pakistan's tribal areas against the killing of Bin Laden by US forces.
The protesters marched through Wana in South Waziristan, carrying placards which denounced the US and the Pakistani government.
Later, White House spokesman Jay Carney said Washington took Pakistani complaints seriously but added: "We also do not apologise for the action that this president took."
He said Mr Obama was convinced that he had the "right and imperative" to mount the raid.
Mr Carney also said the US was still seeking access to three of Bin Laden's widows, currently in Pakistani custody.
In an interview broadcast on Sunday, President Obama told CBS's 60 Minutes show that the al-Qaeda leader must have had "some sort of support network" in Pakistan, but he did not know whether it included government officials.
"We don't know whether there might have been some people inside of [Pakistan's] government, people outside of government, and that's something that we have to investigate and, more importantly, the Pakistani government has to investigate," the US president said in the interview, which was conducted on Wednesday.
The BBC's Natalia Antelava, in Washington, says Mr Obama's message was even-handed and diplomatic, and he was careful not to accuse Pakistan of harbouring Bin Laden.
Pakistan plays a crucial role in America's war efforts in Afghanistan, and too much public pressure on Pakistan could jeopardise the relationship, she adds.
American officials have been poring over computer files seized by US special forces from the hideout.
US officials said the Abbottabad compound was a command and control centre from where Bin Laden had actively led al-Qaeda.