GARHI KHUDA BAKHSH, Pakistan Hundreds of thousands of 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.

A sea of mourners, some wailing and beating their chests in a wrenching outpouring of emotion, flooded through security checkpoints into the mausoelum in rural southern Garhi Khuda Bakhsh for the commemoration.

But thick fog stranded tens of thousands on the roads leading into the area, prompting authorities to delay the start of the proceedings due at 0900 a.m., as they made special arrangements to bring mourners to the site.

Dozens of people kissed Benazirs 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.

Benazir Bhutto was killed in a gun and suicide 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 Peoples Party (PPP) to power in parliamentary elections.

Benazir is buried alongside her father Zulfikar Ali Bhutto, a former premier who was hanged in 1979 by the countrys military regime. Her brothers Shahnawaz and Murtaza, who died in violent circumstances, are also buried in the tomb.

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

Her widower, Asif Ali Zardari, took over the PPP after her death and was elected president in September, facing a crushing economic crisis and soaring violence by militants also blamed for attacks on US and NATO forces in Afghanistan.

Zardari, in a statement marking the anniversary, said the attack on his wife was an attack on the viability of the state and aimed at undermining efforts to build democratic structures and to fighting militancy.

The tyrants and the killers have killed her but they shall never be able to kill her ideas that drove and inspired a generation to lofty aims, Zardari said.

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.

Some even slept Friday night in the open in near-freezing temperatures.

Tariq Waseem, a 25-year-old student from southwestern Balochistan province, walked about 400 kilometres over 10 days with about a dozen friends in order to be at Saturdays event. But unlike his friends, he walked barefoot.

These are not painful, he told AFP, pointing with pride at blisters covering his soles. These are a gift from my martyred leader.

Ceremonies are expected to culminate with special prayers at 0520 p.m. —about the time Benazir was attacked.

A special wall has been erected around the mausoleum as part of a raft of precautions taken to safeguard President Zardari. Closed-circuit cameras have been installed, and mourners were required to pass through metal detectors.

All entry and exit routes were cordoned off.

I was at the rally where she was assassinated. It is my duty to be here on her anniversary, said Maqbool Hussain, 75, a PPP activist with a picture of Bhutto stuck to the front of his shirt. She is my leader. She is leader of all of Pakistan.

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

The government has declared Saturday a national holiday in Bhuttos honour, and events were scheduled nationwide.

At United Nations headquarters in New York, Secretary-General Ban Ki-moon said Friday he was hopeful a UN commission will be established in the near future to investigate Benazir Bhuttos killing .

The government at the time, led by President Pervez Musharraf, blamed Baitullah Mehsud, a 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.

The PPP and Zardari demanded a UN probe.

UN deputy spokeswoman Marie Okabe said the UN 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 UNs 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.