Up to 200,000 Pakistanis gathered at the mausoleum of former Prime Minister Benazir Bhutto on Saturday on the first anniversary of her assassination, some of them walking hundreds of miles to get there.

Dozens of people kissed Bhutto's grave, which was strewn with flowers. Some were beating their heads and chests and wailing. One man burst into tears.

"I am taking these flowers to take home and will show my daughters this gift and this is for blessing," said 41-year-old Saifullah Khan.

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Bhutto was killed in a gun and homicide bomb attack as she was leaving a rally in the garrison town of Rawalpindi, just outside the capital of Islamabad on Dec. 27, 2007.

She was campaigning to return her Pakistan People's Party to power in parliamentary elections, a scenario supported by the United States, which admired her secular credentials.

Her assassination shocked the world, fanning revulsion at rising militant violence in Pakistan as well as conspiracy theories that the country's powerful spy agencies were involved.

Her widower, Asif Ali Zardari, took over Bhutto's party after her death and was elected president in September, facing a crushing economic crisis and soaring violence by militants also blamed for attacks on U.S. and NATO forces in Afghanistan.

He was to speak to mourners later Saturday.

Sher Mohammad, 23, was among many supporters who trekked hundreds of miles to pay respects. "She gave her life for the people of this country, so we can walk a few miles to pay homage to her dignity," said Mohammad, whose feet were swollen from the trip.

Police officer Tanveer Odho said between 150,000 to 200,000 were estimated to have turned out at the mausoleum Saturday.

At United Nations headquarters in New York, Secretary-General Ban Ki-moon said Friday he was hopeful a U.N. commission will be established in the near future to investigate Bhutto's killing .

The government at the time, led by President Pervez Musharraf, blamed Baitullah Mehsud, a Pakistani militant commander with reported links to Al Qaeda, citing a communications intercept in which Mehsud allegedly congratulated some of his henchmen. A Mehsud spokesman has denied any involvement.

Bhutto's party and Zardari demanded a U.N. probe.

U.N. deputy spokeswoman Marie Okabe said the U.N. Secretariat "has been in consultations with the government of Pakistan to determine the nature of the commission, the scope of its mandate and the modalities for its establishment."

The Security Council, the U.N.'s most powerful body, must authorize any investigating commission.

"The secretary-general is hopeful that, with the progression of the discussions, the commission could be established in the near future," Okabe said.