PESHAWAR, Pakistan - Former Prime Minister Benazir Bhutto said yesterday that she would use economic as well as military means to defuse Pakistan's pro-Taliban insurgency, warning that "foreign forces" could invade unless the government curbs spreading militancy.

She was speaking to journalists in the country's troubled northwest, where over the weekend she launched her Pakistan People's Party's campaign for Jan. 8 parliamentary elections.

Another opposition leader and former prime minister, Nawaz Sharif, is urging a boycott of the vote. He and Bhutto are to meet today. She has said she will boycott only if all opposition parties do.

Sharif, who returned last week from seven years of overseas exile, led rallies yesterday of thousands of supporters in Lahore and the nearby town of Phoolnagar.

He denounced President Pervez Musharraf, accusing him of blindly following Washington's dictates.

In her remarks, Bhutto raised the specter of militants moving on Islamabad and gaining control of a key nuclear installation - widely seen as an unlikely scenario.

While playing on fears of a violation of Pakistan's sovereignty, her remarks also reflected her willingness to sustain Pakistan's unpopular military operations against al-Qaeda and Taliban fighters in its lawless tribal regions bordering Afghanistan.

"If Pakistan has no control in the tribal areas, then tomorrow foreign forces can come there," Bhutto said in Peshawar, a stronghold of religious parties. It was an apparent reference to U.S. and NATO forces operating on the Afghan side of the border.

Bhutto also said economic development is crucial to defusing the pro-Taliban insurgency in the impoverished north, where soldiers have clashed with insurgents.

"We will use the military in the tribal areas, but we disagree that a military operation is the only solution to the problem," Bhutto said.

The Musharraf government, which has been promised $750 million in U.S. aid, says it is already promoting road-building and other development projects in the tribal regions that are regarded as the likely hiding place of al-Qaeda leaders Osama bin Laden and Ayman al-Zawahiri.

But its inconsistent tactics, which in the last two years have swung from heavy-handed military action to failed efforts to make peace with pro-Taliban forces, have only alienated tribesmen.

Bhutto warned yesterday against allowing the insurgency to spread.

"Whatever is happening in . . . the tribal area today, that can come to Islamabad tomorrow. And will the world look on as spectators . . . [if] Kahuta falls into their hands?" Bhutto said, referring to the site of Pakistan's main nuclear installation.

Pakistan's Foreign Ministry yesterday issued a statement in response to a British newspaper report on the safety of its nuclear weapons, saying there was no danger of them "falling in wrong hands."

Other opposition parties have threatened to boycott the ballot unless Musharraf reinstates about a dozen Supreme Court judges he fired after declaring emergency rule Nov. 3. A boycott would be a blow to efforts to return Pakistan to democracy after eight years of military rule.

Musharraf, who was army chief, overthrew Sharif in a 1999 coup and became president. In October, he was elected to another five-year term in a disputed parliamentary vote. He stepped down as army chief last week and said emergency rule will end Dec. 16.