Garhi Khuda Bux, Feb 7 : Pakistan People's Party Co-Chairman Asif Ali Zardari has vowed to take revenge of the murder of former premier Benazir Bhutto in a democratic way.

Addressing the chehlum of Benazir Bhutto here, he said: "Our leader Benazir always attempted to effect change in the prevalent system, we will change this system at all costs as this was the mission of Benazir Bhutto."

"We will avenge Benazir's martyrdom in a democratic way. If I succeed, you will see me alive. If I am martyred like her, you will be the ones to take my coffin to the grave," he said.

Vowing to commemorate her every year, Zardari said: "Benazir always said that politics is my worship, accordingly; she was martyred while praying."

He maintained that now the politics turned into a sacred mission, which he would fulfil at all cost.

Tens of thousands of people beat their chests in anguish at Benazir's tomb on Thursday as they marked the end of 40 days of mourning for the slain former premier.

Heavy security was in place for the ceremonies in the rural southern village of Garhi Khuda Bakhsh, where Benazir Bhutto was buried the day after her assassination on December 27, 2007.

Hundreds of paramilitary troops and police stood guard, while walk-though scanners were set up to check the crowds flooding into the mausoleum to throw rose petals over her grave.

Despite the warnings, and the bitter cold, many visitors including women and children stayed overnight in tents before rising at dawn to recite verses from the Quran.

People arrived on foot - some from towns hundreds of kilometres away - and others by trucks and buses. Many were listening to cassettes of Bhutto speeches.

PPP provincial leader for Sindh province Nisar Khauro lamented what he called the government's "double standards" following reports that it was negotiating with those blamed for Benazir's killing.

The PPP has said it will officially begin campaigning from Thursday for the polls, the Dawn reported.

ANI