GARHI KHUDA BAKHSH, Pakistan (Reuters) -- Hundreds of thousands of supporters of former Pakistani Prime Minister Benazir Bhutto gathered in her home town to mark the first anniversary of her assassination.
The anniversary of the killing that shocked the country and sparked days of violence by her supporters, comes as Pakistan faces yet another crisis.
Tension has been rising with India over last month's militant attacks in the Indian city of Mumbai, stoking fears of conflict between the nuclear-armed neighbors.
Bhutto, 54, was killed in a gun and bomb attack in the city of Rawalpindi as she emerged from an election rally just over two months after she had returned from years of self-exile.
In February, the two-time prime minister's Pakistan People's Party (PPP) rode a wave of sympathy to win an election and it now heads a coalition government. Her widower, Asif Ali Zardari, has become president.
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.
A year after her murder, many questions remain unanswered. Investigations by Pakistan's previous government, British police and the U.S. Central Intelligence Agency accused an Al-Qaeda-linked militant of killing Bhutto, a staunch supporter of the U.S.-led campaign against Islamist militancy.
But many of Bhutto's supporters have expressed dissatisfaction with those investigations and are perplexed as to why the PPP-led government has done virtually nothing to get to the bottom of the case.
The new government has asked for a UN commission of inquiry into the assassination, and on December 26, Secretary-General Ban Ki-moon said he hoped an inquiry could be set up in the near future.
Pakistan has said it wants the inquiry to identify "the culprits, perpetrators, organizers, and financiers behind the assassination...with a view to bringing them to justice."
Pakistan wants the proposed inquiry to be modeled on a UN investigation of the 2005 assassination of former Lebanese Prime Minister Rafik al-Hariri. Although a court has been appointed to try indictees in that case, no suspects have been named.
Bhutto escaped unhurt from a suicide attack hours after returning home on October 18 last year. Nearly 140 people were killed in the attack on her welcoming procession in Karachi.
She had spoken of Al-Qaeda plots to kill her. But she also had enemies in other quarters including among the powerful intelligence services.
Bhutto was buried at her family's ancestral graveyard in the village of Garhi Khuda Bakhsh, in Sindh Province, next to her father, former Prime Minister Zulfikar Ali Bhutto, who was hanged in 1979 after being deposed in a military coup.
Her two brothers, Murtaza and Shahnawaz, who both died in unexplained circumstances, are also buried in the mausoleum she herself had ordered built.
Security was tight in Garhi Khuda Bakhsh. Senior police official Tanvir Odho said 6,000 police officers and hundreds of paramilitary soldiers were on guard.
Bomb-sniffing dogs had swept the site, where Zardari is due to address a rally later in the day, and surveillance cameras and walk-through bomb detectors been set up, Odho said.
Odho estimated that 200,000 people had gathered and many of them milled about outside the mausoleum.
"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."
In 1988, aged just 35, the Harvard- and Oxford-educated Bhutto became the Muslim world's first democratically elected woman prime minister. Deposed in 1990, she was re-elected in 1993 and ousted again in 1996, amid charges of corruption she said were politically motivated.