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

Bhutto was speaking to journalists in Pakistan's troubled northwest, where she launched her campaign this weekend for Jan. 8 parliamentary elections. She planned key talks Monday with another opposition leader, Nawaz Sharif, who is urging a boycott of the vote.

Bhutto also raised the specter of militants moving on the capital, Islamabad, and gaining control of a crucial nuclear installation — widely seen as an unlikely scenario.

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

That fight has been spearheaded by President Pervez Musharraf — an important U.S. ally — to tackle militants who fled Afghanistan after the U.S.-led invasion in 2001. The jihadists have regrouped and expanded, threatening Pakistan's own security.

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

Bhutto also said economic development was crucial to defusing the pro-Taliban insurgency in the impoverished north, where Pakistani soldiers have clashed with insurgents in areas including the Swat valley, once a favorite tourist spot, 160 kilometers (100 miles) from Islamabad.

Security forces have killed about 220 fighters in Swat over at least the past 10 days, said army spokesman Maj. Gen. Waheed Arshad. The army also reported arresting 26 suspected militants Sunday.

"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 people of tribal areas are our own people. We want to bring them into the modern age by giving them progress and prosperity."

The government, promised US$750 million (euro508 million) in U.S. aid, says it has that same strategy and claims to be already promoting road-building and development works in the tribal regions — regarded as likely hiding places of al-Qaida leaders like Osama bin Laden and Ayman al-Zawahri.

But the government's inconsistent tactics, which in the past two years have swung between heavy-handed military action to failed peace-making efforts with pro-Taliban forces, have only alienated many tribal people.

Bhutto, a rival of Musharraf but one who shares his liberal, pro-Western outlook, has drawn flak in Pakistan for comments made before returning from exile. She said she would cooperate with the U.S. military in targeting bin Laden if Pakistan could not do the job alone.

That kind of talk has put her — like Musharraf — in the cross-hairs of Islamic militants. Suicide bombers struck at her October homecoming parade in Pakistan's largest city, Karachi, killing more than 140 people.

Bhutto warned against letting the insurgency spread.

"Whatever is happening in Swat and the tribal area today, that can come to Islamabad tomorrow," she said. "And will the world look on as spectators ... (if) Kahuta falls into their hands?" She was referring to the site of Pakistan's main nuclear installation, just east of the capital.

Pakistan's Foreign Ministry issued a statement Sunday 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."

Bhutto's presence in Peshawar, soon after unveiling her party's election manifesto, prompted a massive security operation involving hundreds of police and private guards. She urged indigenous ethnic Pashtuns to forsake militancy and support her secular Pakistan People's Party.

Other opposition parties have threatened to boycott the coming election unless Musharraf reinstates about a dozen Supreme Court judges he fired after declaring emergency rule Nov. 3. The opposition parties say free and fair elections are impossible without an independent judiciary and election commission.

A boycott would be a serious blow to U.S.-backed efforts to return Pakistan to democracy after eight years of military rule. Musharraf has said emergency rule will end Dec. 16 — as demanded by Washington and the opposition.

Bhutto and Sharif, another former prime minister, planned to meet Monday in Islamabad to discuss the election boycott. She has said she will only boycott the vote if all opposition parties do the same.

Sharif, who returned last week from seven years of overseas exile, led thousands of supporters in rallies Sunday in the eastern city of Lahore, his political stronghold, and in a nearby town. Sharif accused Musharraf of blindly following Washington's dictates, and of "crushing" Pakistan's Supreme Court because he feared it would scupper his plans to prolong his rule.

"Today Pakistan is in danger," Sharif told supporters of his Pakistan Muslim League-N party. "One individual is out to destroy the country for the sake of his lust for power."

Musharraf overthrew Sharif in a 1999 bloodless coup. Musharraf was elected for another five-year term as head of state in October. On Wednesday he stepped down as military chief and retired from the army.