Islamabad, 6 May (AKI) - By Syed Saleem Shahzad - Pakistani opposition leader Chaudhary Nisar Ali Khan reacted to the killing of Osama bin Laden by American special forces by declaring the act a national tragedy and demanding the resignation of many of Pakistan's top leaders.

“This is the biggest tragedy in the history of Pakistan after the fall of East Pakistan in 1971 (now Bangladesh)," he said. "heads should roll. Those who breached the sovereignty of the country by the US intrusion in the country, including the president, prime minister, minister of defence and minister of interior should immediately resign,” he told reporters in front of national parliament in Islamabad on Friday.

Much of Pakistan's mood can be described as deeply shocked by the 2 May raid on bin Laden's compound by an American Navy SEAL team in the upscale town of Abbotabad. The operation was reputedly carried out without the knowledge of Pakistani authorities because of the suspicion by Washington that they could tip off the Al-Qaeda leader.

Mass demonstrations in Pakistan were called for Friday to protest the killing of bin Laden, while the country's biggest Islamist political party, Jamaat-e-Islami, called for protests s against what it said was a violation of Pakistan’s sovereignty by the US raid.

The operation has further strained relations between the US and Pakistan as some American officials say that bin Laden could not have been living in a relatively luxurious mansion close to capital Islamabad without the knowledge of authorities. At the same time, many Pakistani's are indignant at the accusations and angry over a perceived breach of sovereignty by the Navy SEAL squad.

Soem 1,500 Pakistani Islamists demonstrated on Friday against bin Laden's killing near Quetta, saying he other figuressimilar to him would emerge to wage holy war against the US.

Pakistani foreign secretary Salman Bashir on Thursday warned of "disastrous consequences" if the US staged a similar attack on its territory.