Blamed Radical 'Capable of Doing Such Things'

"By all accounts, she was here in Pakistan to make a joint government with Perez Musharraf on the U.S.'s instructions, and to extend and serve the U.S. agenda in the region," Shah said. "Her speeches were clearly indicating her tilt toward the United States, and there was an increasing fear among mujaheddins that she may launch more vigorous military operations than Pervez Musharraf at the behest of the United States."

Bhutto had been outspoken about the need for Pakistan to confront Islamic extremism, warning in dire terms that groups such as the Taliban and al-Qaeda pose an existential threat to the nation.

For years, the ability and willingness of insurgents to strike within Pakistan appeared to be limited. But both seem to be growing, and the results have been devastating, with several hundred Pakistanis killed in attacks in the past six months. The pace and scale of the strikes picked up after the military raided the Red Mosque in Islamabad in July, an operation that Bhutto supported.

An October attack on Bhutto's homecoming from exile -- which claimed at least 140 lives -- employed powerful explosives in two blasts. The attack, also blamed on Mehsud by some government officials, bore similarities to the strike that killed Bhutto on Thursday.

The military has allegedly made several unsuccessful efforts to kill or capture Mehsud. In 2005, the government cut a peace deal with Mehsud -- one that locals in South Waziristan say only made him stronger. Mehsud backed out of the deal after the Red Mosque raid.

"This deal with the government made Mehsud the uncrowned king of Waziristan," said Noor Mohammad Wazir, a resident of South Waziristan's main town. "Now he is running the whole show, and Pakistani troops are just spectators."

Witte reported from Karachi.