The al-Qaeda network in Pakistan now increasingly consists of 'homegrown' militants bent upon destabilising the nation and creating political disarray, according to security officials and experts.

In previous years, Pakistani militants directed their energies against American and NATO forces across the border in Afghanistan and avoided clashes with the Pakistani Army, a report in the New York Times said.

But this year they have expanded their ranks and turned to a direct confrontation with Pakistani security forces while also aiming at political figures like former prime minister Benazir Bhutto [Images], who died when a suicide bomb exploded as she left a political rally on Thursday, the report said.

A steady stream of threat reports also spiked in recent months, American officials in Washington said, adding many of them concerned possible plots to kill leaders like Bhutto, President Pervez Musharraf [Images] and Nawaz Sharif.

The expansion of Pakistan's own militants, with their fortified links to al-Qaeda, presents a deeply troubling development for the Bush administration and its efforts to stabilise this volatile nuclear-armed country, the newspaper said.

While Bhutto had begun to acknowledge the threat posed by religious extremism and terrorism, many in Pakistan had been loath to admit it, it said.

On Saturday, Sharif, now the country's most prominent opposition figure, ventured to the political stronghold of his assassinated rival to lay a wreath on her grave.

But, the newspaper said, it was also to make common cause against President Musharraf and the Bush administration's support of him.

Senior American intelligence officials told the newspaper that all credible threat information in recent weeks had been passed to Pakistani authorities mainly through the US embassy in Islamabad.

However, the officials said they were not aware of any specific reports of an attempt on Bhutto's life in Rawalpindi.

A senior American intelligence official was quoted as saying it was clear from his reading of recent threat reports that "the political process was not going to go untouched", adding that militants almost surely would go to any length to create political disarray.

The tribes on the border, the newspaper noted, have a long history of fighting invading armies.

But since 2001, when Qaeda and Taliban forces fled the American intervention in Afghanistan and took refuge in Pakistan's tribal areas, the Pakistani militants have steadily grown in strength and boldness.

Presently, they were bolstered by the foreigners among them which included a smaller number of hard-core Arabs, like Osama bin Laden and Ayman al-Zawahri, al-Qaeda's second in command, as well as a larger number of Uzbeks, Tartars and Tajiks, Pakistani security officials said.

The Arabs in particular have brought money and fighting and explosives expertise, as well as ideology that includes religious justifications of tactics like suicide bombings and beheadings, which Afghans and Pakistanis had not used before, they were quoted as  saying.