Leaders of Al Qaeda (search) and the Taliban (search) have held a series of meetings in Pakistan to discuss how to disrupt Afghanistan's upcoming elections, the U.S. military said Monday.

"Relatively high-ranking" members of both groups as well as rebel Afghan faction Hezb-e Islami Gulbuddin (search) have held several meetings on how to derail the Oct. 9 vote, spokesman Maj. Scott Nelson said.

Citing intelligence reports, Nelson said the meetings were marked by growing alarm at intensifying efforts on both sides of the Afghan-Pakistani frontier to root out their activities.

"There have been several meetings between Taliban, Al Qaeda and HIG members in Pakistan where they've raised serious concerns" about efforts to track them down as well as how best to attack the election, Nelson said.

Nelson said the participants in the meetings were "relatively high-ranking" but wouldn't elaborate, nor specify where they took place.

He said it was "certainly" possible that Usama bin Laden (search) and other leaders of Al Qaeda were in the rugged border region.

Maj. Gen. Eric Olson, the operational commander of the U.S.-led force in Afghanistan, said this month that he had no fix on where bin Laden or his deputy, Ayman al-Zawahri (search), were at.

But he said he believed that the Al Qaeda leaders were still pulling some of the strings in the stubborn Afghan insurgency.

Olson cited a car bombing which killed about 10 people, including three Americans, at the office of a U.S. security firm in the Afghan capital last month.

Election workers have also been targeted, with 10 killed so far in a string of bombings and shootings, but the violence has failed to prevent millions of Afghans from registering to vote.

Nelson said the militants were divided over how best to thwart the election, which U.S.-backed interim President Hamid Karzai is widely expected to win.

"They talk, but I don't know how cohesive their strategies are," he said.

He said militants were also debating how to counter muscular operations by both the Pakistani military and Afghan and U.S. forces.

Thousands of Pakistani forces have carried out a string of bloody offensives in the Waziristan tribal region next to the border, bombing a suspected training camp and killing scores of suspected militants.

Nelson praised the Pakistani military for "very aggressive operations in the areas where we think these senior leaders are hiding. They've had quite a bit of success."

He said U.S.-allied forces had intensified their campaign against militants in neighboring Paktika, Paktia and Khost provinces of Afghanistan.

Pakistan's army spokesman was not immediately available for comment.