Pakistani Prime Minister Imran Khan has come under fire from opposition MPs after telling parliament that the US "martyred" Osama Bin Laden.

Bin Laden, the mastermind of the 9/11 attacks, was killed in 2011 when US special forces raided his hideout in the Pakistani city of Abbottabad.

Pakistan was not informed in advance.

"I will never forget how we Pakistanis were embarrassed when the Americans came into Abbottabad and killed Osama Bin Laden, martyred him," Khan said.

Khan used the word "shaheed" - a reverential Arabic term for a martyr of Islam.

Opposition leader and former Foreign Minister Khawaja Asif criticised Mr Khan, calling Bin Laden an "ultimate terrorist".

"He destroyed my nation, and [Khan] is calling him a martyr," Mr Asif said in parliament.

Bilawal Bhutto Zardari, whose Pakistan Peoples Party was in power when Bin Laden was killed, accused the prime minister of appeasing violent extremism.

Meena Gabeena, a high-profile Pakistani activist, wrote on Twitter: "Muslims all over the world are struggling because of the discrimination they face due to recent terrorism and our PM makes it worse by calling [Osama Bin Laden] a martyr of Islam!"

Mr Khan's speech came as Pakistan's foreign office rejected a US state department report accusing Pakistan of continuing to be a safe haven for regionally focused terrorist groups.

"While the report recognizes that al-Qaeda has been seriously degraded in the region, it neglects to mention Pakistan's crucial role in decimating al-Qaeda, thereby diminishing the threat that the terrorist group once posed to the world," the foreign office said.

Mr Khan, a former cricketer, has previously been criticised as sympathetic towards the Taliban, and branded "Taliban Khan" by opponents.

Following his controversial Bin Laden remark on Thursday, Afrasiab Khatak, a nationalist former senator and former head of the independent Human Rights Commission of Pakistan (HRCP), said in a tweet that the prime minister had been brought to power to implement "Project Taliban".

In a TV interview four years ago, Mr Khan refused to call Bin Laden a terrorist when pressed by the interviewer.

Analysis: M Ilyas Khan, BBC News, Islamabad

Imran Khan called Osama Bin Laden a martyr not because of any ideological commitment to the 9/11 mastermind but because it was politically convenient.

The world has come a long way from the politics of 9/11, but Islamist militancy is still seen by analysts as the main weapon of Pakistan's powerful military establishment to push for its perceived aims in India and Afghanistan.

Bin Laden and other senior al-Qaeda and Taliban leaders of that time are still revered by the militants, and they function as useful tools in recruiting people to the cause. Any move to officially downgrade Bin Laden's status therefore could be counter-productive.

Mr Khan is seen by his critics as close to the military establishment - a proxy who has been catapulted to power in a 2018 election allegedly rigged by the military.

His word choice on Thursday was not an accident. Many noted that during his speech he initially used the word "killed" for Bin Laden, then stopped himself and corrected to "martyred".