ISLAMABAD - Fighter jets pounded Taliban militants in Pakistan's troubled northwest, killing 40 militants as ground troops tried to flush them from their fortified hideouts, the army said Saturday.

The five-month-old civilian government initially opened peace talks with insurgents -- something former president Pervez Musharraf also briefly tried before his Aug. 18 resignation -- but has since resorted to what some are calling all-out war.

The insurgents have responded with a wave of suicide bombings, including one targeting a massive weapons factory near the capital that left 67 dead, most of them civilians.

Army spokesman Maj. Nasir Ali said at least 40 Taliban were killed Friday when fighter jets pounded militants in Swat Valley, once a popular tourist destination and now the scene of some of the fiercest fighting.

A cache of ammunition exploded when it was hit in one of the strikes, he said, adding that ground troops were advancing into the region Saturday to root out other militant fighters.

Taliban spokesman Muslim Khan said eight of his men, including a local commander, were killed.

The violence followed news that Asif Ali Zardari, who seems poised to be voted Pakistan's next president in a Sept. 6 election by legislators, had moved into a tightly guarded government compound because of security fears.

His late wife, Benazir Bhutto, a two-time former prime minister and an outspoken critic of Islamic extremism, was assassinated in a Dec. 27 gun-and-bomb attack during a campaign rally.

Their Pakistan People's Party has sought to assure the United States that it remains committed to battling terrorists since the ouster of Musharraf, a close U.S. ally who resigned rather than face impeachment.

Officials say more than 400 militants have been killed this month alone. There are no separate statistics for civilians, but witnesses say dozens have died. More than 200,000 others have been forced to flee their homes, most of them women and children.

Many are living in sweltering, mosquito-infested relief camps.

Human rights groups expressed concern Saturday about the rising violence.

Most of the displaced are from Bajur, a rumoured hideout of Osama bin Laden, but citizens are also fleeing Swat, where they say they face risks from both militants and government air strikes.

Locals "insist there is no targeted operation against militants, rather it is a haphazard armed invasion on the people of Swat," Asma Jahangir, chairwoman of the Human Rights Commission of Pakistan, wrote in a letter to the prime minister.

"They have given numerous examples where militants could have been apprehended or attacks on civilians could have been averted had the security forces acted with diligence," she wrote.

The Taliban, meanwhile, have threatened to intensify a campaign of suicide bombings unless the operations cease. They have carried out three deadly strikes in recent days, including one on a hospital and another on a police post.