The Pakistani government quickly hailed the death of Osama bin Laden as a "major setback" to global terrorism, but the killing of the world's most notorious terrorist near its capital Islamabad is seen to increase pressure to Pakistan which has long been suspected of aiding terrorist groups.

Bin Laden was killed by U.S. forces in the mountainous resort town of Abbottabad, inside a mansion near a military academy and less than two hours drive from the capital.

In a statement, the Pakistani government said, "Osama bin Laden's death illustrates the resolve of the international community, including Pakistan, to fight and eliminate terrorism. It constitutes a major setback to terrorist organisations around the world."

It was not clear if the Pakistani military participated in the dramatic night-time raid by the U.S. forces. But the silence of Islamabad on the death of bin Laden for several hours hints that it was also taken by surprise and was not aware of the operation.

Relationship between Islamabad and Washington has been strained in recent months over attacks by U.S. drones and CIA activities in the country which sometimes result in the deaths of civilians, including women and children. The U.S. and its allies have long suspected and accused Pakistan of providing aid to militants targeting U.S. troops in Afghanistan.

In fact, Pakistan's influential intelligence agency the ISI, is suspected of maintaining links to al Qaeda's precursor, the Haqqani network, which was organized 1980s.

Pakistani security analyst Imtiaz Gul commented, "For some time there will be a lot of tension between Washington and Islamabad because bin Laden seems to have been living here close to Islamabad.

"If the ISI had known, then somebody within the ISI must have leaked this information," Gul said. "Pakistan will have to do a lot of damage control because the Americans have been reporting he is in Pakistan ... this is a serious blow to the credibility of Pakistan."

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